This is something I had mulled over for a while. What could possibly be the best controller this generation? I had to really evaluate the controllers I own and the last few days gave me a clear winner. The Xbox One Controller. It suprised me initially, but thinking about each controller, there was no real doubt. 

THE WII U GAMEPAD

I started off this generation with the Wii U Pro Controller and Gamepad. I really liked the gamepad. This pic is the version I have. The weight felt about right. The symetrical control sticks and button placement worked really well. I really liked how the button and triggers felt. Same for the gyro and touchscreen controls, though they were used less frequently. When it had it, I loved asymetrical play. Off TV play was at times essential. I think liking the controller really helps appreciate the system, so if you don't like it, I can see why you may not like the system.

THE WII U PRO CONTROLLER

The Pro controller, on the other hand was somewhat above servicable. It was a direct recreation of the Gamepad. I think what hurt it, for me, was that they retained the symmetrical controls. It was nowhere near as comfortable, and the button size and placement was hurt because of it. I think what is also clouding my judgement was that I always had friends over who would sometimes rage drop the controller during smash, and 2 of them now ocassiioanly mess up.

The texture made it really easy to see the dirt, thus making it really easy to clean.

THE DUAL SHOCK 4

The PS4 controller... I tried but I don't like it. I have never liked the Dual Shock series, and despite this being my favorite so far, it is still easily the most discomfort I have had playing video games. I hate symetrical controls and this is worse that the Wii U one by more than a margin. At least with the Pro Controller it was on top. With the DS4, the sticks are on the bottom. Making it really uncomfortable to use. The sticks themselves I like a lot. It has a nice feel to it as well as functionality. The buttons felt great. I still don't like that the use shapes instead of A,B,X,Y, but it felt really good. I think I like the control pad here more than the control pad on the Wii U Pro. I don't know why. I really dislike the option and start button placement. The touchscreen... button... thing in the middle was a bizzare choice to me and the only place that I feel is not an improvement to the previous controllers in the series.  The triggeres were refreshing. Differently shaped, but still worked really well.

The grip on this thing was amazing, though I must say. I imagine the controller was set up the way it is, JUST to have those grips feel so good.

THE XBOX ONE CONTROLLER

The XBox One Controller was, at a time dead last. I used it on a booth once, and I was so disatisfied. More than disatisdied, I was dissapointed. Especially since the 360 controller was my second favorite controller last gen. Since then I have never touched the controller until a couple of days ago.

I went to  help a friend with moving and construction because I finished my work for the week a couple days early and hadd nothing better to do. Afterwards before I left he gave me a belated Christmas present.

The Xbox One Controller. I thought it was pretty neat because earlier another friend broke my Xbox360 controller so I thought it was pretty good to have. I started using it the other day. I must say that it was miles better than my first impressions with controller. Honestly I don't know why. Maybe because it was stationary on a booth? I digress.

The controller has 3 core improvements I love:

Control Stick

Control pad

Triggers.

The control sticks especially were the best improvement. The tire-like distinction from its predecessor make if feel so much better. Don't feel any slip like I did with my 360 controller, and I really doubt I'm gonna have the same wearing over time issue either.

The bumpers are ok. Very nice and springy. I guess I don't like as much as anything else due to the fact I can really feel and hear the spring. A cheap complaint I know.

Now the triggers are amazing. I need to look back on the 360 controller, but they definitely somehow made it feel much better. I don't think this is the best improvement, I still think that goes to the sticks, but this may very well be my favorite change. It just feels so good to use and press.

I don't like the icons for the pause and select button, but I do really like their placement on the controller. The Xbox button is great where it is as well.

The overall grip on the controller is good to. This is one of the things I initially Microsoft got wrong, but after actually using it for an extended period, it feels great. Not the best, but definitely an improvement. I think the PS4 controller trumps it in this regard.

The only thing I don't like about the controller is the texture. I still feel the Wii U gamepad and pro controller are the best in that regard, but I think I may be alone on that one.

Overall I think that this may be the best controller of the generation

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------

There you have it. Out of the controllers I actually own, this is how I came to my conclusion. I would compare keyboards and mice, but really they are generationless, Much more importantly I never really had enough space, believe or not, for proper keyboard and mouse support. 

If you have multiple controllers, what is your favorite?

EDIT:

A lot of people are ranking their controllers, which is something I forgot to do earlier, I'll just rank mine now for clarity on my opinion

4) DS4

3) Wii U Pro

2) Gamepad

1) Xbox One

Edit: Added a poll because people wanted it.

Of the ones I own...

DS4
Pro Controller
Xbox One S controller
A roll of barbed wire
Gamepad

I would say the Wii U Gamepad for its multi functionality! But its buttons and analog sticks kinda sucks.

However, The Pro Controller fixes that! It was light, long battery and the buttons were nice to press.

The best controller is the one each individual finds the most comfortable.

It's a tie for me between the PS4 and Wii U Pro. The PS4 has better triggers and is overall quite comfortable but the battery life for a normal old controller is pretty bad. The Pro is light, comfortable and has an astounding 80 hour battery life.

I actually do quite like the Gamepad, it's comfortable enough and the touch screen and off tv play are nice features. But it's nearly as comfortable as the others and of course the battery life is terrible.

I didn't try the wii u pro controller so I gotta pick the DS4 despite it having the analog stick at the bottom and the d-pad and the top, I will say tho the wii u d-pad is probably my favorite d-pad of all time.

As an owner of all three. Xbox One for me in terms of preference of analog sticks. DS3 to DS4 is a massive gap in quality. Wii U gamepad... yeah... not a fan.

DS4 is disappointing to me. The angle of the handles make the controller awkward to hold when using the thumbsticks. Also, concave analogue sticks are objectively worse than convex!

I only have the wii u gamepad and ps4 controller but i have used the xbox one controller. Out of the 3 i only like the ps4 controller

They all have pros and cons.

The GamePad has a lot of neat features but the L/ZL and R/ZR triggers/bumpers are super awkward.

The DS4 is a big improvement over DS3, but the stick placement is so uncomfortable. I shouldn't have to contort to play a game.

Pro Controller has great battery life but it's a little on the simplistic side.

XOne controller has the asymmetrical sticks I love plus a good grip and triggers. D-pad and bumpers are just ok.

So I'd rank them

4) GamePad
3) DS4
2) WiiU pro
1) XOne