It wasn't released this year, hence it cannot be GOTY.

Mario Kart 8
- The visual was a BIG improvement from the wii
- its like Mk7 but multiplayer
- I love the gravity stuff
- New items (i like the pirahnna plant)
- I enjoyed watching highlights on the mk tv

NES Remix 2.

Yea, it will probably be Bayonetta 2 if Inquisition doesn't beat it out.

3D World was last year!

Hyrule Warriors for me, here is how I would order them though (note that I love all of them)
1. Hyrule Warriors
2. Smash Bros for Wii U
3. Tropical Freeze
4. Mario Kart 8
5. Bayonetta 2

Smash Bros without question. Very likely to be my GotY period. I'll have to see if it'll usurp Brawl as my favourite in the series.

While I'd still give the best platformer I've ever played award to Mario Galaxy, Tropical Freeze is definitely in my top 5.

Donkey Kong Country: Tropical Freeze

Looks great, tight controls, challenging levels, amazing soundtrack, hard mode which is the most rewarding experience ever for a platformer. I 200% this game, beating every world din normal and hard mode. Finding every K letter and getting every puzzle piece. One of my favorite games of all time.

I'd probably go with Mario Kart so far but it's hard to pick between it and Tropical Freeze. I haven't played Shovel Knight yet but I hear it's awesome. I'm sure Bayonetta 2 will be good and I'm really looking forward to Captain Toad as well. And Smash, well, I know it'll kick ass.

WiiU sure does have some epic quality games throughout 2014, droughts be damned.

EDIT:  Sorry, Curl... I didn't specify why, lol.  I'd go with Kart because I love the series and I think the WiiU version has the best selection of new tracks of any entry.  Outstanding production values as well.  For people who prefer Smash over Kart though, I can understand why that would be their choice because it looks like a fan's dream entry as well.