Wii Kart is pretty fun. You gotta take it a bit lightly, lest you get annoyed because your winning run was screwed by a well timed power up going to another character.
THIS! If you have a major lead in the last leg, you'll get destroyed by about 15 different powerups and end up in 7th place... frustrating as hell...
I'm a big lover of Metroid. Your typical FPS, but with different controls that makes it more 'natural'. Granted, I played the first two, and loved them... so it was a continuation of story for me...