Earlier quoted context omitted.
Gamecube was all about the controller. Besides the PS4 controller, the Gamecube is still the most comfortable controller ever. Buttons all felt great as well.
I kind of prefer the Steam Controller honestly. After getting used to it even the DS4 feels akward.
Maybe I'd get used to it, but based on only a half-dozen hours or so, the "D-Pad" on it is possibly the worst directional input I've ever used, and the analog stick sticks out too far. The controller body is great, and everything else is fine, but directional inputs are probably the most important feature.