Bear in mind this is my list, these are my opinions and I'll respect yours if you respect mine. Also I don't own a Wii or a PS3.

XBOX 360: Dead Rising 2

A really fun game which has an excellent amount of replayability.

PSP: A tie between Metal Gear Solid Peace Walker and Valkyria Chronicles 2

I couldn't pick just one because both of them are so great in their own aspects. While I was really excited to play Peace Walker, VC2 really took me by suprise and I'm really loving it.

DS: Pokemon Heartgold

Practically the only DS game I purchased in 2010, and I got to say, it's good, but the series is getting incredibly stale and I kinda got bored with this one after beating it. Though, it is a remake of my favorite game of all time, so no complaints.

Honorable mentions to some other awesome games I played:

Super Meat Boy (360)

Naruto Ultimate Ninja Storm 2 (360)

Call of Duty Black Ops (360)

Pac Man Championship Edition DX (360)

Sonic 4 Ep 1 (360)

God of War Ghost of Sparta (360)

Honestly, I didn't really play that many games this year. I try to play the games that are less known rather than playing all of the super popular ones, with the exception of Black Ops. So yeah, 2010, great year for gaming though I wish I could've played more. See yah later!