Advance War: Dual Strike is a MUST
MarioKart as well (best version to date)
Puzzle Quest
Those should eat up a solid four to six months of your time (especially if you have friends to play against)
My End of 2008 Hardware Predictions (console only):
Wii : 50 million
360: 28 million
PS3: 24 million
These predictions were made on January 3rd and won't be revised