In my years of playing games, the closest any controller has ever come to perfection is the Japanese Saturn pad. The best d-pad I've ever felt coupled with the proper 6-face buttons and 2 shoulder buttons. I bought 2 of the PS2 Saturn pads when they came out last year and since then fighting games have been heaven on the PS2. When the Dreamcast came out, my first thought was "Why didn't they just use the NiGHTS Saturn controller? That was pretty much perfect". Seriously, give that controller a better analog stick and a VMU slot and it would have been a perfect version of the DC pad.
The PS2 controller is, overall, really good, with only the mucked-up d-pad and lack of 6 face buttons marring it. 4 face buttons is fine for action games, but if you want to play Street Fighter on that system, you better have an arcade stick or PS2 Saturn pad handy.
I really really love the GC pad, but the analog stick and c-stick having those notches inside their movement hole makes using them a little awkward to me. I love how the grips are shaped, though, it's like a more ergonomic Dual Shock. I just wish they'd put 4 top buttons on it instead of 2 big ones and a little tiny z-trigger. I don't even mind the d-pad (I played all the resident Evil games on GC using the pad, I find running around with the analog stick in those games impossible to steer).
I never play FPS games on consoles, I HAVE to have mouse/keyboard. Trying to aim with an analog stick is like trying to write with my left hand (I'm right handed).
The worst pads I've ever used are the regular Xbox pads (worst button placement ever, you need dislocated thumbs to use the white and black buttons well) and the N64 pad (analog stick would break at the drop of a hat, and the buttons were pretty poor).