Best controller?
But, as for pads, my current favorite is the Logitech premium controller for PS2, with the leather grip inserts, gold plated plugs, etc. Mine crapped out, though, gotta find a new one.
The shape of the PS3 controller looks good to me, as it's somewhat similar to my PS2 controller.
Favorite that I've used, however, is the fullsize XBOX controller. It's just the right size that I don't get hand strain from having to tightly clamp my hands around the controller, and the buttons are well laid out, unlike the horrible B/W buttons on the S model.
Worst controller "honors" go to the 3DO's pad.
Only a pad and five buttons (A,B,C on the front, and two shoulder buttons), on a console that was released concurrently with PS1 and N64, and absoultely apalling build quality. Both the general feel and the buttons feel like they came off one of those $20 "1000 games in one!" sets they sell in the mall, absolutely insane considering the price of the console, in excess of $500. (May have been $599?) I'm glad I got mine for free at the time, as a family member was a VP at a Panasonic-related company,)