Tough one between 3D World, Mario Kart, or WW. People who chose X are silly. It's impressive in scope, and pretty good graphics to boot. But on a simply graphical level - it isn't that great compared to the others.
3D World looks like it was made with plastic. And not to mention that the weird aliasing flicker of Mario Galaxy is still present and looks even worse now for some reason. If anything, Wind Waker is the best looking game on the Wii U.
I disagree on all fronts, because I'm not liking anything from Mario 3D World so far. To me, it looks like everything got wrapped up in plastic, and I'm seeing no innovation in the gameplay. At this point, I don't think I'll like it at all next to Galaxy 2.
Even though I'm hesitant to whether I'll like Lost World's gameplay against Generations (my favorite game of gen 7), I'm still happy that they're not playing it safe. I'm looking forward to making some new speedruns, and spending a few hundred more hours trying to crack the top 25 on the leader boards.
I think the plastic look you guys speak of is meant to the rain which drenched up Mario's hat and overalls. If you look at the pictures where he looks plastic you can also see water effects against the screen suggesting it was raining. It's a realistic weather effect which nobody should have any problems with.
Surprised nobody has brought up Donkey Kong Country Tropical Freeze. The developers (Metroid Prime trilogy) knows how to utilize the hardware they're working with quite well. I'm sure the game (as with the others mentioned in poll) will look much better closer to release.