There have been 57 playable characters in the Street Fighter series. That's...a hell of a lot considering it only began with a handful. And even by Street Fighter II the number was only at 8-12.
Blame the later games, when Capcom went a little crazy.
This awesome poster by artist Ken Wong puts all 57 of them in the one stylist place, and includes a little guide down the bottom telling you who's who.