The Gamecube controller is the one that feels the best in my hands. The only issue is that the buttons aren't very nice for slide inputs in fighting games, but I don't play many fighting games on Gamecube anyway. And by not many, I mean none at all. As a close second, there's probably the Dualshock family. I'm sure I could get used to the x360 controller too, but I just don't have one to get used to.