And why?

Wonderful 101, mainly cause of the epic boss fights. 

Wonderful 101 or Lego City Undercover
Wonderful 101- Epic boss battles, interesting gamepad functions, steep learning curve with no hand holding,a real challenge.
Lego City- Full of charm and humour, well written, huge game with tons of collectables, still the Wii U game i own with the longest gameplay time logged at 50+ hours.

Guess I'd say Monster Hunter.

Because it's pretty good.

I haven't played ZombieU or W101 so I can't comment on them, but Monster Hunter 3 is pretty good on the U. I stopped playing it a while back ,but it was an awesome time

Lego City Undercover, it was fun and played it the most

*reads thread title*

Mario Strikers: Charged

I've not played lego city or zombiu and never got into monster hunter 3 u though might be worth giving it another shot when i have free time.

1. W101 (For the most part it was amazing. Just didn't like the punchout and shoot em up bit's they threw in.)
2. Trine 2 (The use of the Gamepad worked brilliantly in the wii U version of this pinnacle of indie excellence.)
3. Stick it to the man (A great adventure game. Only just played through it and loved it but it'll probably settle lower in my estimation with time.)
4. AC4 (Anything that reminds me of windwaker... even if only a little bit)
5. Rayman Legends. (Loved both singleplayer and multiplayer. I'd sing this games praises more if others weren't hyping it up a little to much.)

Eid: Actually Deus Ex hr would be my number one but I played it on PC

Can I vote for MonHun3 Ultimate?? Ive never played it but I played MonHun3 on Wii.
Otherwise my answer is nothing, I only own Nintendo games and very few of them.