Super Smash Bros. Character Info

SUPER SMASH BROS.
(http://img4.wikia.nocookie.net/__cb20110928153010/ssb/images/3/3a/SelectionScreenSSB.png)

Characters: Luigi, Mario, DK, Link, Samus, C. Falcon, Ness, Yoshi, Kirby, Fox, Pikachu, Jigglypuff.
There are 12 selectable characters.

SUPER SMASH BROS. MELEE
(http://www.ssbwiki.com/images/f/f8/Character_selection_melee.png)

Characters: Dr. Mario, Mario, Luigi, Bowser, Peach, Yoshi, DK, C. Falcon, Ganondorf, Falco, Fox, Ness, Ice Climbers, Kirby, Samus, Zelda, Link, Young Link, Pichu, Pikachu, Jigglypuff, Mewtwo, Mr. Game & Watch, Marth, Roy.

There are 12 veterans and 14 newcomers.
There are 25 selectable characters. But there are 26 playable characters, including Sheik.

SUPER SMASH BROS. BRAWL
(http://img2.wikia.nocookie.net/__cb20131124044703/ssb/images/9/93/Character_Selection_-_Super_Smash_Bros._Brawl.png)

Characters: Mario, Donkey Kong, Link, Samus, Kirby, Fox, Pikachu, Marth, Mr. Game & Watch, Luigi, Diddy Kong, Zelda/Sheik, Pit, Meta Knight, Falco, Pokemon Trainer, Ike, Snake, Peach, Yoshi, Ganondorf, Ice Climbers, King Dedede, Wolf, Lucario, Ness, Sonic, Bowser, Wario, Toon Link, R.O.B., Olimar, Captain Falcon, Jigglypuff, Lucas.

There are 21 veterans and 18 newcomers.
There are 35 selectable characters. But there are 39 playable characters, including Sheik, all 3 Pokemon separately, and Zero Suit Samus.

SUPER SMASH BROS. WII U/3DS
(http://www.smashbros.com/us/index.html#CharacterList)
(http://www.ign.com/wikis/super-smash-bros-wii-u-3ds/characters)

Characters: Mario, Donkey Kong, Link, Samus, Kirby, Fox, Pikachu, Pit, Villager, Mega Man, Wii Fit Trainer, Pikmin & Olimar, Luigi, Peach, Toon Link, Sonic the Hedgehog, Marth, Rosalina & Luma, Zelda, King Dedede, Lucario, Little Mac, Diddy Kong, Zero Suit Samus, Sheik, Yoshi, Charizard, Greninja, Ike, Mii Fighters, Palutena, Pac-Man, Captain Falcon, Lucina, Robin, Meta Knight, Shulk, Game & Watch, Wario, Bowser Jr. (Koopalings), Ganondorf, Ness, Falco, Dark Pit, Dr. Mario, R.O.B., Duck Hunt, Jigglypuff.

There are 34 veterans and 15 newcomers.
There are 49 selectable characters, and only 49 playable characters.
You start out with 37 characters, and have to unlock 12 characters.