Oh hay, great year for gaming this year.
Super Mario Strikers - my brother actually got this, but since I can beat him up it's pretty much mine. Best muliplayer game I've played in quite some time.
Mario Tennis: Power Tour - same situation as above. Pretty cool, great handheld tennis.
Naruto 4 - Not actually a christmas gift, but I got it around christmas and I didn't pay for it! Pretty cool, yay for fighting!
Kururin Squash - same situation as above. Sorta disappointing. I'd rather use skill to get through tricky puzzles then hitting enemies with a boxing glove...
1080 Avalanche - I'm having a blast with this game, I was not prepared for the sense of speed this game delivers.
Battalion Wars - Holy crap, this is hard. I suck at this game so much, II'm never goign to get anywhere in it.
Luigi's Mansion - launch title like what

For the DS~
Castlevania - woah. I was not prepared for how awesome this game is. It's my first Castlevania, and Ima definitley pick up the GBA compilation whenever it comes out.
Trauma Center: Under the Knife - I love this game. The dialogue can get annoying at times, but the operations are awesome.
Advance Wars DS- I haven't played this one too much, but I'm liking it a bit more than AW2, even though this one's basically the same except on steroids.
Partners in Time - Haven't played too much of this one either, but it's pretty cool so far. That's all I have to say about that.