The Street Fighter IV modding community has gotten into re-skinning characters in a big way, producing every skin imaginable from Duke Nukem to Gandhi to Jill Valentine.
Street Fighter IV mods for the PC version have blown up in a big way, first with the move set switching mod that let you do things like graft C. Viper's graceful maneuvers onto Zangief's hulking bod and now with the unsurprising appearance of a massive number of fan made re-skins for every character.
Judging from the thread on the SRK forums, Cammy and Chun-Li enjoy the most popularity (no big surprise there), but dig around a bit and you'll find some really cool (and really weird) stuff. Sure, I'm a fan of the Jill Valentine skin for Cammy, but who can deny seeing Guile as Duke Nukem, Seth as Venom, Sagat as Kratos, Dhalsim as Gandhi, or, my personal favorite, Zangief as Mr. T.
There's also some stuff that should have been obvious to me but never was, like making Blanka into Beast from X-Men, as well as things that never would have occurred to me to imagine in a million years, like giving Balrog a red nose and coloring his skin blue and red so he looks like popular anime/manga character Doraemon.
Forget getting a game out to the widest possible audience. This, my friends, is the real reason you bring your games to the PC.