1. Monster Hunter Tri Ultimate
2. Super Mario 3D World
3. Pikmin 3
4. New Super Mario Bros. U / Super Luigi U
5. Nintendo Land
6. ZombiU
7. Nano Assault Neo
8. Spin the Bottle: Bumpie's Party
-snip-
9. The Wonderful 101
10. Sonic Lost World
I really feel like most people, especially those that don't own a Wii U, or just recently bought it, underrate just how good Nintendo Land can be. Not just for the 'party games', but the single player offerings are stellar too.
I added the snip under 8 because I wouldn't really put W101, or Sonic on my recommended list for the Wii U's first year, but I just didn't have much else to add. Notably other titles I considered, Toki Tori 2, which didn't click with me too well and Dungeons & Dragons, which was fine for what it was.
Obviously the odd choice on the list is Spin the Bottle: Bumpie's Party. But it really is quite an entertaining title for the price. That is, if you have people that will actually want to play it, since the games are sometimes weird, odd, hilarious and anything, but what you would expect from a video game.
http://www.youtube.com/watch?v=zTC6h2IG1CA&t=7m45sOverall, I enjoyed the Wii U plenty for the first year. I think for a gamer, it had plenty to offer, even with the early drought. But for joe-public and more casual fans of games, it still doesn't have 'that' game to bring them in.