I loved SFII on the Super Nintendo. I never got into the whole third party controller market though, I rocked the original SNES controllers for it. I did, with Soul Calibur on Sony PlayStation, purchase a special controller to use.

I agree, I believe Street Fighter II coming to their console was a big reason to release a 6 button controller. I know NEC did too, in Japan, for their PC Engine when they secured Street Fighter II for their platform.

I love these improvements. They are powered by fans "just because". There is no financial drive, no ceiling based on deadlines, just a fan, or fans, improving a game because they want to.