All except my GC controller are clean. My GC controller is pretty bad though, the grip on the control stick was torn off six or seven years ago by a stupid nephew and the little holes to put a new one on are broken. It's got crap in practically every groove on it too, but it's my launch GC controller and has lasted me all this time whilst two others have broken, so I can't bear to part with it and get another one :D

Mine is kind of dirty, I've been thinking of cleaning it actually.

I said hop in...

My pet peeve when it comes to video games is sticky/dirty controllers. I rarely eat while I'm playing.
I don't want the buttons to get sticky. That bugs the hell outta me. My rule is no greasy foods when playing. That rule applies to my friends as well. I only make few exceptions.

Some dust around the corners, but I wipe the controller from time to time.