Honestly kind of a rough call, considering how few games there actually were. But here goes:
2012: NSMBU - Great game, even though I liked NSMBWii better.
2013: Super Mario 3D World - Fun game, nice to have the SMB2 lineup back, though I wish they would have gone all out with the SMB2 influence, and just had the game take place in Subcon again, with more SMB2 bosses/enemies, including Wart. Would have made the game more memorable, instead of merely good.
2014: Hyrule Warriors - When this game was announced, I honestly didn't think all that much of the idea, because I've never been super into the Warriors series. But I got it, and it's damn fun. Put a lot of hours into it, might even be my most-played Wii U game, in sheer hours. I might have given it to Mario Kart 8, because the RACING part is great, but to me, it's held back from being ALL it could have been, by the piss-poor, phoned-in "Battle" mode. Shovel Knight also deserves a mention, but it's not Wii U exclusive. So Warriors gets it.
2015: Kind of a rough year to be honest, but I guess Yoshi's Wooly World deserves the nod. Somehow I haven't enjoyed it AS much as I did Kirby's Epic Yarn, but it's still a very solid game.
2016: Also rough, but I'll give it to Twilight Princess HD. I would have preferred that this game received the same kind of HD treatment that WW got, and it kind of pisses me off that it didn't get it. But it's still a good game, even IF they made some incredibly retarded choices, like making Rupees from chests just disappear if your wallet is full.
IF Breath of the Wild had come out in 2016 for Wii U like it was supposed to, I have a feeling it would have won GOTY hands down. And for all I know, it might still wind up being game of the SYSTEM, considering the fact that I'll likely not be getting a Switch anytime around launch. It's only too bad the game didn't come out with Wii U actually needed it, instead of as a sad afterthought.
