I seen this article over at EventHubs that you can now play SFII: Championship Edition in your web browser. You will probably need the latest version of Adobe Flash to play it. I think they are doing this so people will buy SFIV on PC. Anyways, play this game to remember the good old days. It actually runs really good for a flash game.
I don't mind playing with a keyboard. As with anything it's a matter of practice. But I wish it was programmable, as I would like the directions on the WASD keys. I'll just have to play reverse seth killian style.
As for gamepads, just make your button presses translate to key presses with whatever software like PPJoy.
Edit: Ha, I actually find it pretty easy to do the quarter circle and such motions with the arrow keys, I find it harder to coordinate my left hand's fingers for the actual punch and kick key presses xD