I'm playing it on pc with an xbox controller. Its definitely worth getting one. I use it for all kinds of games Grid, Dirt 2, racing games its a must. Batman AA, Just Cause 2, Grand Theft Auto 4, Darksiders. There the sort of games that dont require precision aiming but more, analogue controls, and quick responses.
I'm used to controllers though(came from consoles to pc), I can play fps with a controller although I prefer a mouse for aiming. Its also nice to be able to sit back instead of being hunched over the keyboard.
Think i'll have to grab darksiders and a controller.
I have the logitech gt5 steering wheel, not sure its PC compatable, guess i should invest in gt5 though, some of the Crysis screenshots are amazing on here.