The PS2 was by far the best for me. No matter what game I played, the controls responded perfectly.
The Fat XBOX controller sucked. The S controller was a major improvement for me.
The Gamecube controller fits my hand nicely. Until I played games on it. Platform games rock on the GC controller. Any other game is next to impossible. Fighting games (i.e. Soul Calibur II) are extremely difficult to play because I had a tendency to jam on the humongous "A" button. First Person shooters were extremely difficult to play with the GC controller. The camera stick was too sensitive. The problem with the Gamecube controller was the buttons. The A button were three times larger than the the X and Y buttons. I can't count the times I pressed A instead of X. The L and R buttons on the side are difficult to wield. You have to push the button ALL the way in order to get a reaction. God forbid you played a game where you had to hold the shoulder button in conjuncture with another button for long periods of time. (i.e. Enter the Matrix, Spider Man 2). I hope the next controller is better.