There is no one game that sold me on the Wii U, but the promise of what's to come (3-D Mario, Zelda, X, Pikmin 3 before it's release) and the thrill of surprises like Bayo 2, Wonderful 101 and that which we don't yet know about.
If I had to pick one though, I'd want to say that Zelda demo, but 13 years ago I learned the hard way not to trust Nintendo when it comes to Zelda demos.







