I prefer a keyboard/mouse or joystick to any console controller, but if I had to choose, I would probably go with Xbox. I cannot stand the 4 billion shoulder buttons on the PS2.
Yeah, that's probally what I'll use it for. Old Nintendo emulators and such.
It's not very good in FPS, plus I can't figure out how to assign the player's pitch/yaw settings to the gamepad. I could emulate a mouse with it, but that's ghetto.