I've only have the Wii U Gamepad and the Wii U Pro Controller.

And I would say the Wii U Gamepad. I love new stuff. And the Gamepad feels very new. Its also what sold me the Wii U. The way that some games where you can just play on the gamepad instantly is quite amazing! The touch controls are quite good too.

The buttons on the gamepad just needs to improve (Not like Nintendo will continue this). Like they should have put the similar buttons on the Wii U pro controller to the gamepad. (not sure if its possible though)

If / when I get a DS4 where the thumbstick rubber doesn't wear after a few months of low intensity use then I would be happy to vote DS4. But I am disappointed with having to get thumbstick covers which diminish the ergonomics of the thumbstick and thus make the controller less than what it should be.

Also I have no direct experience with the other controllers so I don't really qualify to vote.

Nah, the gamecube's d-pad is way too small :-/ but overall it feels great in the hands, so I could understand why people like it.

Inalways loved the play station controllers, even before the dualshock was released, people don't even notice them anymore because they're so present and have been the default input device onthe most common consoles for so long now, but there is a reason they have barely changed over the years, this was an amazing design to begin with, both responsive and comfortable.... Plus they are feature complete! 

Anyway, I think all modern "regular" controllers are great, saying one trouncesthe others like many insist is just unfair, I have some preference, but none is a real problem formost games...

Wii U Pro Controller

If the wii u pro controller could be used to operate the console and as the main controller for all games it'd be my favorite.

Given that isn't the case, I feel like it's a three way tie... The gamepad is an awesome controller for the wii u and the ps4/xb1 controllers are pretty much the same experience. Excellent controllers all around this gen.

The dualshock 4 is the best controller ever

the wii u

As far as features and usability go, saying anything other than the Wii U GP would make you look nuts :P

I figured you'd probably live in the US, cause as you know your country has a strong Xbox/PC culture indeed. Here people prefer the XB1 controller as well, but I've noticed a big change worldwide on the internet since the DS4 appeared.