The Gamecube controller is one of the best controller designs ever created. It was super comfortable and the button layout was perfect/gorgeous.
My only gripe is that when they went to Wii they completely changed the controller design and I never got the opportunity to see a perfected GCN controller design. I hope the next Nintendo console uses and updated Gamecube style controller. This is coming from somebody who thinks the 360 controller and PS4 controller are near perfection.