Every Single Cameo In Ready Player One

Video Games
Pac-Man/Ms. Pac-Man: The cherries is seen as a sticker on Samantha's Oasis visor. A Ms. Pac-Man sticker is seen on Art3mis' Akira bike. In Aech's basement there is an Arcade cabinet of Pac-Man.
Q*bert: A Q*bert sticker can be seen in Wade's hideout van.
Joust : The knight on the ostrich is seen in the crowd of Oasis civilians during the final battle. In Aech's basement there is an Arcade cabinet of Joust.
Space Invaders: A graffiti of multiple invaders are on a brick wall in Ohio. James Halliday wears a Space Invaders t-shirt. On Wade's OASIS visor there is a sticker of the logo from Space Invaders.
Centipede: A scorpion can be seen taking out the knight on the ostrich and carrying its rider. A centipede Arcade cabinet can be seen in Aech's basement.
Street Fighter : Ryu is seen on walking the Oasis racetrack. Blanka is seen in the Oasis nightclub. Both Chun-Li and Sagat are seen in the crowd of Oasis civilians during the final battle. Street Fighter characters are seen as stickers on Samantha's Oasis visor.
Battletoads : Zitz, Rash, and Pimple are seen in the crowd of Oasis civilians during the final battle.
Duke Nukem : Duke Nukem is one of the Oasis civilians taken out by Aech during the PVP fight.
Tomb Raider : Lara Croft is seen in the Oasis nightclub and later during the final battle.
Battleborn : El Dragón, Toby, and Ambra are seen in the crowd of Oasis civilians during the final battle. Attikus, Benedict, and Miko are seen walking around the Oasis.
Mass Effect : The male and female versions of Commander Shepard are seen at the Oasis nightclub and later during the final battle.
Overwatch: Tracer is seen during the final battle in the Oasis and can also be seen briefly in the Oasis zooming into a portal. Mercy is also seen during the final battle. In the Oasis Mall an Overwatch stall can be seen. Doomfist and Soldier 76 are seen walking around in the Oasis. Widowmaker, Mei, Hanzo and Sombra are seen destroying an IOI spider.
BloodRayne: Rayne can briefly be seen to the left next to Lara Croft during the final battle in the Oasis.
Angry Birds: Red and Bomb are seen flying into battle in the Oasis. The Iron Giant uses the slingshot to launch Parzival during the final battle.
Mortal Kombat : Raiden, Cassie Cage, Kitana, and Scorpion are seen in the crowd of Oasis civilians during the final battle. Sub-Zero and Johnny Cage are seen walking on the Oasis racetrack. Liu Kang can be seen being killed by Aech during the PVP fight. A Mortal Kombat sticker can be seen on Akihide’s shirt.
Halo : Master Chief, a group of Spartans, and an Elite are seen in the final battle. When Aech is in the PVP zone, he uses a Halo Aussalt Rifile. During the final battle, Parzival is seen summoning a SPNKR Rocket Launcher from Halo 1-3. In the Oasis Mall a Halo stall can be seen.
StarCraft : A Protoss is briefly seen walking in the Oasis, behind Hello Kitty and her friends. Jim Raynor is also spotted during the PVP fight. A Sectoid also appears in the Oasis behind Tracer waiting in line. Zealot can be seen right behind Protoss.
Devil May Cry: Danté is seen during the final battle amongst the Oasis civilians. Parzival looks exactly like Dante.
Captain Commando: The titular character can be seen during the final battle.
Legend of Zelda: Link, Zelda, and Ganondorf are seen during the final battle.
Metroid: Samus Aran is seen in the crowd of Oasis civilians during the final battle as well as in the nightclub, dancing next to Art3mis.
BioShock: A Big Daddy is seen during the final battle.
Final Fantasy VII : Cloud Strife is seen during the final battle.
Bayonetta : The titular character is seen during the final battle.
Mega Man : The titular character is briefly seen during the final battle in the Oasis.
Super Mario Bros/Mario Kart: Mario riding Yoshi and Bowser are seen during the final battle. Luigi is seen riding his kart at the Oasis racetrack. Aech also mentions Mario Kart while talking to Wade.
Minecraft: Herobrine and a Creeper are briefly seen during the final battle. A Minecraft Stall can be Seen in the Oasis Mall
Sonic the Hedgehog: The titular character is seen during the final battle in the Oasis and can also briefly be seen waiting in line for access to a portal in the Oasis. A Sonic stall in the Oasis Mall can be seen. Knuckles is seen at the Oasis nightclub.
Fire Emblem: Marth and Ike are seen in the Oasis nightclub and during the final battle. Corrin can be seen entering a PVP portal in the Oasis.
Skylanders: Gill Grunt, Drobot, and Torch are seen during the final battle in the Oasis. Blaster-Tron can be seen entering a PVP portal in the Oasis.
Kirby: The titular character is seen during the final battle.
Pokémon: Parzival is seen throwing a Poké Ball at the Batmobile during the race. A Poké Ball also appears very briefly when being thrown up in the air when Wade is introducing the Oasis.
Half-Life: Gordon Freeman is seen during the final battle.
God of War: Kratos is seen during the final battle.
Tomb of Horrors: A large sticker of the logo is on the back of Aech's hideout van.
Uncharted: Nathan Drake is seen during the final battle.
Resident Evil: Chris Redfield and Jill Valentine are seen during the final battle.
Donkey Kong: Donkey Kong can be seen on a poster in a girl's room.
Star Fox: Fox McCloud is seen during the final battle.
Darkstalkers: Jedah Dohma and Morrigan are seen during the final battle.
Metal Gear Solid: Solid Snake is seen in the nightclub.
F-Zero: Captain Falcon is seen getting in the Blue Falcon on the Oasis racetrack.
Pikmin: Olimar is seen in the Oasis nightclub.
Kid Icarus: Pit and Palutena are seen during the final battle.
Earthbound: Ness is seen fighting a Sixer during the final battle.
Punch-Out: Little Mac is seen during the final battle.
Xenoblade Chronicles: Shulk is seen during the final battle.
Five Nights at Freddy's: In the PVP zone, there is a silhouette of Nightmare Freddy.
Shovel Knight: The titular character is seen in the Oasis.
Monkey Ball: Ai Ai is seen during the final battle.
NiGHTS: The titular character is seen during the final battle.
Splatoon: Parzival is seen using Inkling-based weapons during the final battle.
Portal: GlaDos is mentioned by Aech during the final battle. Wheatley can be seen flying around in the Oasis.
Ghosts 'n Goblins: Firebrand can be seen flying around in the Oasis.
Final Fight: Mike Haggar can be seen during the final battle.
Strider: Strider Hiryu can be seen during the final battle.
Dead Rising: Frank West can be seen walking around in the Oasis.
Soul Calibur: Ivy is seen during the final battle.
Bionic Commando: Spencer can be seen in the Oasis nightclub.
Dino Crisis: Regina can be seen during the final battle.
Okami: Amaterasu can be seen walking in the PVP portal.
Fatal Fury: Mai Shiranui is seen during the final battle.
Crazy Taxi: B.D. Joe is briefly seen on the Oasis Racetrack getting into his Taxi.
Dark Souls: A Mushroom Parent and a Mushroom Child are briefly seen entering the Oasis.
Gears of War: Myrrah is seen during the final battle.
Borderlands: A Borderlands shop is seen in the Oasis Mall.
Left 4 Dead: Hunter, Boomer and Tank are seen during the final battle.
Dead Space: A Necromorph is seen during the final battle.
Fallout: Prime Liberty appears during the final battle.
LittleBigPlanet: Sackboy appears during the final battle.
Undertale: Sans can be seen during the final battle in the Oasis.
The Literature Club: Emi and Minobu can be seen in the Oasis Mall.
Knack: Ice Knack assists Parzival in the final battle.
Doom: Doomguy can be seen during the final battle.

Movies
The Iron Giant: The Iron Giant is seen during the final battle in the Oasis.
Back to the Future: Parzival is seen driving a DeLorean outfitted with KITT. In Aech's Basement there is a replica of the Hoverboard from Hill Valley 2015. When Art3mis is about to exit Aech's garage Art3mis refers Parzival to Marty McFly and does the helmet pose before exiting.
Akira: Art3mis drives Shotaro Kaneda's motorcycle.
Chappie: The titular character can be seen during the final battle.
King Kong: King Kong is seen as one of the stage hazards in the Oasis racetrack.
Mad Max: The Interceptor car is seen as one of the vehicles in the Oasis racetrack.
A Nightmare on Elm Street : Freddy Krueger is one of the Oasis civilians taken out by Aech in the PVP fight. A poster of the film can be seen in Wade's hideout van.
Conan the Barbarian : The titular character is briefly seen in the Oasis nightclub.
Aliens: Ellen Ripley in her yellow mech suit and a Xenomorph are seen in the crowd of Oasis civilians during the final battle.
Batman (1989 film): The Batman logo can be seen as a sticker on Wade's Oasis visor. The Batmobile featured in the film is in Aech's garage. In a scene Parzival climbs Mount Everest with Batman. In a weapon selection room spinning around is a batarang. A Mini-Batman sticker can be seen on Akihide's Oasis visor.
Christine: The titular car can be seen amongst other famous vehicles in the Oasis racetrack.
Army of Darkness : The Deadites are seen in the Oasis battlefield.
Superman: Parzival dresses up as Clark Kent.
Marvel Cinematic Universe: Rocket Raccoon and Groot are seen in the Oasis nightclub. The Winter Soldier is seen taking out a scorpion.
Child's Play: Chucky is amongst the Oasis civilians seen during the final battle.
Say Anything...: Parzival is seen holding the boombox from the film.
Hellboy: The titular character can be briefly seen during the final battle.
Watchmen: A Watchmen Smiley can be seen as a sticker in Wade's hideout van.
Spawn: The titular character can be seen in the Oasis nightclub.
The 7th Voyage of Sinbad: The Cyclops can be seen during the final battle.
Jurassic Park/Jurassic World: Rexy the Tyrannosaurus Rex can be seen as one of the obstacle hazards in the Oasis racetrack, chasing Aech's monster truck. A Space Invaders Arcade cabinet in Aech's basement has a huge Jurassic Park logo sticker stuck on to it.
Transformers film series: Optimus Prime, Bumblebee, and Nitro Zeus are seen amongst the crowd of Oasis civilians during the final battle. Megatron and Sentinel Prime are seen transforming into vehicle mode on the Oasis racetrack. Onslaught can be seen entering a PVP Portal in the Oasis.
Star Wars: Kylo Ren and Boba Fett are seen amongst the Oasis civilians during the final battle. Darth Vader is seen in the Oasis nightclub. C-3PO and R2-D2 are seen walking on the Oasis racetrack. X-Wings and AT-ATs are seen during the final battle. Han Solo can be seen being taken out by Aech. Darth Maul can be seen fighting Parzival during the final battle. Parzival ignites a blue lightsaber during the final battle. Stormtroopers can be seen in a group working together with a group of Spartans from Halo during the final battle. C-3PO, R2-D2, and Jango Fett can be briefly be seen entering the Oasis.
Classic Godzilla films: Mechagodzilla and Gigan are seen amongst the Oasis civilians during the final battle fighting Iron Giant, Optimus and Gundam. King Ghidorah is seen in New York on the Oasis racetrack as one of the stage hazards. Rodan is seen during the final battle flying over Gundam.
Friday the 13th: Jason Voorhees is seen in the crowd of Oasis civilians during the final battle.
Gremlins: Multiple Gremlins are briefly seen in the crowd of Oasis civilians during the final battle. A poster of a Mogwai (most likely Gizmo) can be seen when the film crew are making the movie Ready Player One. A sticker of a Gremlin is seen in Wade's hideout van.
War of the Worlds: A Tripod is seen during the final battle.
Tron: A Blue Lightcycle is seen on the Oasis racetrack.
Cars: Mater is seen on the Oasis racetrack.
Avatar: A Na'vi is seen during the final battle.
Ghostbusters: The Stay Puft Marshmallow Man is seen during the final battle.
Pacific Rim: Gipsy Danger is seen during the final battle.
Big Hero 6: Baymax is seen during the final battle.
Justice League: Steppenwolf appears in the crowd of Oasis avatars at the Distracted Globe nightclub.
Suicide Squad: Enchantress is seen during the final battle.
MonsterVerse: Godzilla can be seen attacking Megalon in the distance on the Oasis racetrack.
The SpongeBob Movie : The Patty Wagon is seen as one of the vehicles in the Oasis racetrack. Plank-TON appears during the final battle.
Indiana Jones: The titular character is seen during the final battle. There is a replica of the idol from Raiders of the Lost Ark on a shelf in Aech's basement.
Gamera: The titular character is seen during the final battle.
The Shining: There is a Flicksync based on the movie that acts as a quest.
The Neverending Story: Falkor can be seen in the Oasis.
National Lampoon's Vacation: The Griswold Family Truckster can briefly be seen in the Oasis race when Art3mis skids past on her Akira bike.
Mothra: The titular character is briefly seen during the final battle.
Labyrinth: There is a poster of the film in Wade's hideout van.
Cloverfield: Kishin is briefly seen in New York battling King Kong as is also a stage hazard.
Teenage Mutant Ninja Turtles (2010s films): Leonardo and Raphael are seen in the Oasis nightclub, and are later seen next to Parzival in the Oasis. Michelangelo can be seen in the final battle in the Oasis.
Wall-E: The titular character is seen next to Parzival in the Oasis nightclub.
Real Steel: Atom is seen during the final battle.
G.I Joe: Snake Eyes and Duke are seen in the Oasis nightclub.
The Wizard of Oz: The Wicked Witch is seen during the final battle.
Saturday Night Fever: In the Distracted Globe nightclub, there are multiple mini-dance floors based off the film.
The Terminator films: The T-1000 and T-101 are seen during the final battle.
Batman Returns: Catwoman is seen during the final battle.
Toy Story: Buzz Lightyear is seen during the final battle.
Sharknado: Fin Shepard is seen with his chainsaw during the final battle.
Pirates of the Caribbean: Jack Sparrow is seen during the final battle.
The Matrix: Neo is seen giving Wade a mushroom during the final battle. The opening logos for the film has purple patterns of the green text in the matrix. A Matrix poster can be seen among newspaper articles in Wade's hideout van.
The Incredibles: Mr. Incredible is seen in the Oasis nightclub.
Jason and the Argonauts: The Living Skeletons can be seen during the final battle.
Predator: The titular character is seen next to Deadshot during the final battle.
Ice Age: Sid can briefly be seen entering the Oasis. Manny and Diego can be seen during the final battle. Captain Gutt and his crew are also seen in the PVP fight. Scrat can be seen in the Oasis Mall.
Jaws: A poster of a Great White Shark can be seen when the film crew are making a movie called Ready Player One.
Monsters Inc.: Mike Wazowski can be seen at the Oasis nightclub.
Teenage Mutant Ninja Turtles II: The Secret of the Ooze: Tokka is seen during the final battle.
Robocop: The ED-209 can be seen in Aech's garage. The titular character is briefly seen entering the Oasis.
Spaceballs: Eagle 5 can be seen in Aech's garage.
Austin Powers: The upside-down T shaped rocket can be seen taking out the force field on the castle.
Pee-Wee's Big Adventure: His bicycle can be seen in Aech's garage.
Elf: Buddy is seen hopping in the Oasis.
Space Jam: The Monstars are seen during a PVP fight.
Rise of the Guardians: Jack Frost appears during the final battle.
How to Train Your Dragon: Hiccup and Toothless appear during the final battle.
2001: A Space Odyssey: The space pod can be seen in Aech's garage.
Ferris Bueller's Day Off: The red Ferrari can be seen in Aech's garage.
E.T. the Extra-Terrestrial: A poster of E.T. can be seen when the crew are making the film.
Zootopia: Nick Wilde is seen in The Distracted Globe nightclub. Judy Hopps and Chief Bogo appear during the Oasis Copper Key race.
Rock Dog:
The Goonies: The Goonies logo is printed on a James Halliday Newspaper Article. Sloth can be seen during the final battle.
Who Framed Roger Rabbit: Roger Rabbit is seen walking around the Oasis mall. Jessica Rabbit is seen at The Distracted Globe.
Beetlejuice: Beetlejuice appears during the final battle.
Over the Hedge: RJ is seen in the Oasis Mall. Hammy can also been seen during the final battle.
Last Action Hero: Jack Slater III is showing at the theatre.
Clash of the Titans: The Kraken appears during the final battle.
The Breakfast Club: John Bender can be seen walking in the Oasis next to Nightwing.
Wreck-It Ralph: Ralph can be seen during the final battle.
22 Jump Street: Jeff can be seen during the final battle.

Comics/Literature
DC Comics: A Wonder Woman sticker is seen on Art3mis's Akira bike. Deathstroke, Doctor Fate, Poison Ivy, Killer Frost, Wonder Woman, Joker, and Harley Quinn are seen in the Oasis nightclub. Batman, Deadshot, Wonder Woman, Aquaman, Black Manta and Flash are seen in the crowd of Oasis civilians during the final battle. Superman and Robin are seen taking out a Sixer. The Jaime Reyes Blue Beetle is shown walking next to Parzival in the Oasis. A random person in Ohio is wearing a Flash t-shirt. Green Lantern can be seen being taken out by Aech in the PVP fight. Hawkman can be seen multiple times in the Oasis and later during the final battle swooping over Wade's DeLorean. Wade mentions Lex Luthor to Art3mis. Nightwing is seen walking around the Oasis after Tracer enters a PVP portal. A Wonder Woman's Logo badge is on Helen's jacket.
Marvel Comics: Peter Parker and Bruce Banner are mentioned by Parzival. Deadpool, Iron Man, Hulk, Spider-Man, Loki and Thanos are seen in the crowd of Oasis civilians during the final battle. Black Widow and Hawkeye are seen in the Oasis nightclub. Scarlet Witch, Captain America, Wolverine and Doctor Doom are seen chasing a Sixer. The Infinity Gauntlet is seen in Aech's garage. Magneto and Ultron can be seen entering a portal in the Oasis. The Wasp can be seen flying around in the Oasis.
The Lord of the Rings: Gandalf is seen in the Oasis nightclub. A cave troll can be during the final battle in the Oasis. Aech uses an Orc as his selected Oasis avatar.
Harry Potter: The titular character is seen during the final battle.
Hägar the Horrible: The titular character is briefly seen in the Oasis nightclub.
The Maze Runner: A Griever is seen during the final battle. Thomas and Sonya are seen in the nightclub and are also seen confronting Parzival during the Copper Key Race.
The Black Order: Proxima Midnight and Corvus Glaive are seen during the final battle.
Lady Death: The titular character is seen during the final battle.
The Hunger Games: Katniss Everdeen is seen during the final battle.
Garfield: A Garfield sticker is seen inside Wade's hideout van.
Scott Pilgrim: Roxy Richter is seen during the final battle.
Alice in Wonderland: The Jabberwocky is seen during the final battle.
Battle Angel Alita: The titular character is seen during the final battle.

Contemporary
Bigfoot: Aech drives the vehicle on the Oasis racetrack.
Simon (game): The game is seen as a pin on James Halliday's jacket.
Atari 2600: The game console is hanging on a wire in Wade's hideout van. An Atari sticker is on the front of Art3mis's bike.
Madballs: Repville is seen as graffiti in the real world of Ohio.
Hello Kitty: The titular character, Kerropi, and Badtz-Maru can be briefly seen in the Oasis. A sticker decal of the titular character can also be seen on Art3mis's bike.
Warhammer 40,000: Eldar is seen during the final battle.
Hot Wheels: A part of The Oasis Copper Key race is inspired by some hot wheels ramps.
Tsuchinoko: A tsuchinoko is seen double jumping during the final battle.
Laser Tag: The 1980's Laser Tag can be seen in Aech's garage.
Garbage Pail Kids: Lots of Garbage Pail Kids Cards are stuck on the wall of Wade's hideout van.
80's Snacks: In Wade's hideout van, there are wrappers of a M&M's packet and Cheeto's. In an IOI van, there are some 80's Doritos.
Nerf: A Nerf blaster can be seen in Aech's garage.
Apple: A Macintosh computer is among Wade's possession while he's in his hideout.
Gameboy: A Gameboy can be seen in Wade’s hideout van.
Rubik Cube: In the Oasis Mall a shop named the cube with a giant Rubik cube can be seen briefly.
Sega: A Sega sticker can be seen on Art3mis's Akita bike.
Tatio: A Tatio sticker can be seen on Art3mis's Akita bike.
Freddy Freaker: The titular character is seen during the final battle.

TV Shows/Cartoons
The Simpsons: Homer Simpson's Pink Sedan is seen on the Oasis racetrack along with Marge's Canyonero. Bart, Lisa, and Maggie are seen during a Flicksync of the episode The Secret War of Lisa Simpson.
Family Guy: Brian Griffin is seen at The Distracted Globe.
Knight Rider: Parzival's DeLorean is outfitted with KITT.
Mobile Suit Gundam: The RX-78 Gundam mech is seen during the final battle in the Oasis.
Batman (1966 series): The Batmobile from the show is seen as one of the vehicles in the Oasis racetrack.
Digimon: Digital Monsters: Tai Kamiya and Agumon are seen in the nightclub. WarGreymon is seen during the final battle.
The Greatest American Hero: Ralph Hinkley's superhero logo can be seen as a sticker on Art3mis's Akira bike.
The A-Team: The A-Team van is seen as one of the vehicles in the Oasis racetrack.
Speed Racer: The Mach 5 can be seen as one of the vehicles in the Oasis racetrack.
Fairly Oddparents: Cosmo is seen during the final battle.
Danny Phantom: Danny Phantom is seen during the final battle
Doctor Who: The Doctor (portrayed as her thirteenth incarnation) is seen during the final battle. A group of Daleks are seen during the PVP fight.
Spongebob Squarepants: The titular character is seen driving the Patty Wagon with Patrick in the Oasis racetrack.
The Powerpuff Girls: Blossom, Bubbles, Buttercup and Mojo Jojo are seen during the final battle.
Power Rangers: The Megazord is seen during the final battle.
He-Man: The titular character is seen during the final battle. Wade has a He-Man lunchbox in his hideout van.
She-Ra: The titular character is seen during the final battle.
Alf: Alf appears as a Plush toy on Aech's couch in his basement.
Phineas and Ferb: Perry the Platypus is mentioned by Wade.
Thundercats: Parzival wears a belt with the Thundercats logo on the buckle. Snarf appears as graffiti in Ohio.
Breaking Bad: Walter White appears walking down the OASIS.
Voltron: Defender of the Universe: A Voltron Lion is seen during the final battle. The planet Doom can be seen during the final battle.
Neon Genesis Evangelion: The Evangelion Units are seen during the final battle.
Gravity Falls: Bill Cipher is seen during the final battle.
Game of Thrones: Jon Snow and Daenerys Targaryen are seen in the Oasis nightclub.
The Flintstones: Fred Flintstone is seen as graffiti in Ohio.
Naruto Shippudden: Naruto is seen during the final battle.
Dragon Ball Z: Goku is seen during the final battle.
Fairy Tail: Natsu and Happy can be seen during the final battle.
My Hero Academia: Midoriya can be seen during the final battle.
Death Note: Ryuk is seen during the final battle.
Hey Arnold!: Wade mentions it on the list of his favorite TV shows.
The Walking Dead: Negan is seen during the final Battle
Agents of S.H.I.E.L.D: Ghost Rider is seen riding his motorcycle during the Oasis race.
Stranger Things: The Demogorgon is seen during the final battle. Eleven is seen entering the Oasis.
Star Wars: The Clone Wars: Ahsoka Tano is seen during the final battle fighting a Sixer.
Star Wars Rebels: Ezra and Kanan are seen during the final battle fighting a Sixer.
Yoki Watch: Jibanyan is seen during the final battle.
Exosquad: The Exosuit can be seen in Aech's garage.
Pinky and the Brain: Both Pinky and The Brain can be seen as graffiti when the film crew are making the movie Ready Player One.
Captain Caveman and the Teen Angels: Captain Caveman can be seen as a graffiti when the film crew are making the movie Ready Player One.
Cowboy Bebop: The Swordfish 2 can be seen on the official poster for Ready Player One. A miniature version of Swordfish 2 can be seen on the work table of Aech's garage.
Looney Tunes: Marvin the Martian is briefly seen entering the Oasis. A Looney Tunes shop can briefly be seen in the Oasis Mall. Pepé Le Pew is seen with Penelope Pussycat in The Distracted Globe.
Yu-Gi-Oh! Duel Monsters: Yami Yugi is seen during the final battle. Seto Kaiba appears as a Sixer avatar.
Animaniacs: Yakko, Wakko, and Dot Warner are seen in the Oasis Mall. Slappy Squirrel is seen during the final battle.
Jem and the Holograms: Jem is seen in the Oasis nightclub.
Sesame Street: Big Bird and Snuffy are seen walking down the Oasis. Super Grover is seen flying during the final battle.
Warehouse 13: An IOI spider looks kind a like a M.A.R.A. spider.
Attack on Titan: A Titan is seen during the final battle.
Rick and Morty: A Pickle Rick sticker can be seen on Art3mis' Akira bike.
Sinful: Gluttony and Lust are seen in the Oasis Nightclub.
Seinfeld: The movie opens with a stand-up comedy bit from Jerry Seinfeld from inside the Oasis, where Jerry asks "What's the deal with video games anyway?"

Music/Musicians
The Bee Gees: "Stayin' Alive" is played during Parzival and Art3mis' dance routine.
Daft Punk: "Lose Yourself to Dance" plays at The Distracted Globe.
Stormzy: "Big for Your Boots" plays during Aech's chat session.
Wham!: "Wake Up Before You Go-Go" is the sound of Wade's alarm clock.
Miley Cyrus: "Wrecking Ball" The wrecking balls can be seen on the Oasis racetrack as one of the hazards.
Micheal Jackson: Parzival tries out a Michael Jackson outfit before going to the Distracted Globe.
Prince: Before going to the Distracted Globe, Parzival tries out a Prince outfit.
Pink Floyd: Marching Hammers are seen in the final battle.
Duran Duran: Before going to the Distracted Globe, Parzival tries out a Duran Duran outfit.
Hatsune Miku: The titular vocaloid character is seen in the Oasis nightclub.
Buckaroo Banzai: Parzival dresses up in Buckaroo's suit at the Distracted Globe.
Devo: In the Distarcted Globe nightclub the bartender is wearing a Devo hat.
Van Halen: "Jump" can be heard during the trailer for Ready Player One.