Ashley
Astronaut
Wild West Wear
Bearsuit
Biker
Black Knight
Business Suit
Cat Suit
Captain Falcon
Chibi Robo
Tracksuit
Chrom
Ray Mk III
Butler Outfit
Dragon Armor
Dunban
Flying Man
Cybernetic Suit
Isabelle
King K. Rool
KK Slider
Toy-Con
Link Outfit
Champion's Outfit (BOTW Link I assume)
Lip Outfit
Mecha Suit
Maid Outfit
Builder Mario
Fighter Uniform
Bionic Suit
Monkey Suit
Viridi
Nia
Ninja Suit
Pirate Outfit
High-Tech Armor
Protective Gear
Ribbon Girl
Isaac
Saki Amamiya
Samus Armor
SSB T-Shirt
Skull Kid
Special Forces Outfit
Inkling (Male & Female)
Inkling (Male & Female) (SP2)
Spring Man
Fox Outfit
Steampunk Getup
Takamaru
Toad
Vampire
Vince's Outfit (who the fuck is this supposed to be?)
Yiga Clan Outfit
Woolly Yoshi Outfit

HATS (Or at least what seems new/interesting/isn't already listed above):
Arcade Bunny Hat
Cappy
Dixie Kong's Hat
Mr. Saturn
Marx's Hat