Zelda. Because my favorite genre is 3rd person action adventure. I'm going to admit that I haven't played any of the others, but l am almost 100% sure that I wouldn't enjoy them as much as Zelda.
That gorgeus Zelda U is probably the game that's gonna make me buy a Wii U, even if I have to resell it shortly after.
EDIT: Sorry, I forgot that I did play some Mario and Donkey Kong back in the day, in the SNES. But I'm just not into 2D platformers.