Super Smash Bros has easily the best character roster of all time, pretty much only lacking mainstays that are exclusive to other developers.
With 66 different characters through the installments in the series, there is a lot of story and fanservice in this games, and even if you haven't played the games this characters originate from, the game is infinitely enjoyable on its own.
So the question is this GAF, have you played the games this characters originate from? How many of them? How many do you want to play in the future?
Here is a list to make it easier:
Bayonetta
Bowser
Bowser Jr.
Captain Falcon
Charizard
Cloud
Corrin
Dark Pit
Diddy Kong
Donkey Kong
Dr. Mario
Duck Hunt
Falco
Fox
Ganondorf
Greninja
Ice Climbers
Ike
Ivysaur
Jigglypuff
King Dedede
Kirby
Link
Little Mac
Lucario
Lucas
Lucina
Luigi
Mario
Marth
Mega Man
Meta Knight
Mewtwo
Mii Brawler
Mii Gunner
Mii Swordfighter
Mr. Game & Watch
Ness
Olimar
Pac-Man
Palutena
Peach
Pichu
Pikachu
Pit
Pokémon Trainer
R.O.B.
Robin
Rosalina
Roy
Ryu
Samus
Sheik
Shulk
Snake
Sonic
Squirtle
Toon Link
Villager
Wario
Wii Fit Trainer
Wolf
Yoshi
Young Link
Zelda
Zero Suit Samus
As for me, I am only missing Cloud, since I have yet to play Final Fantasy VII and the only FF game I have played was IV. I did play almost everything in this list because of smash, otherwise I would have never discovered gems like Earthbound, Metroid or Fire Emblem.
Oh, and for Japan only games, Fire Emblem GBA should count for Roy, even if he has a small cameo, I guess. I played Mother 3 by importing the game.
That is 65/66 for me. How well did you do?