NSMBWii was a GREAT surprise. I didn't know i can laugh that much with my friends with a simple videogame. God of War III was awesome too. Wii sports is another one.

Metal Gear Solid 4. This is the first game that actually made me care about the characters. An amazing game from a brilliant developer.

MSG 4 no doubt... but like akvod bad company has also made me spend lots of hours in from of the TV and when i bought it i was miles away from the idea that it would grow on me that way and that big!

@OP... U-DF was my first plat so that also made a big impact on me too!

Phoenix Wright: Trials and Tribulations.

Either Gears of War or Bioshock. Gears of War was the first game of this generation that truly felt like a next gen game. The graphics at the time blew everything else away and it shaped online co-op for this gen as well. Bioshock because of the way it changed how a games story is told and Rapture is the one of the best game worlds to be created.

I put the most gaming time in for halo 3 but i think the game that impacted me the most was Uncharted 2. Uncharted 2 was the game that made me switch over from and xbox to ps3!!

My very first game experience on the ps3 would be Uncharted: Drake's Fortune and it was one of those games that had a impact on me. Now Uncharted 2 came out and I didn't expect for them to top the first one and that just left a big smile on my face when playing the game. It's funny that I went for the Uncharted ps3 bundle when I first heard about the game I was making fun of how its a Indiana Jones copy and boy I'm glad I bought it.

The Elder Scroll's Oblivion, it was the first time in my life that I got addicted to a game outside of Pokemon. It also introduced me to WRPG's.

MGS4 made every other game I played after it weird to play, knowing that no game this gen will make me care for a character as much as that game did.

Bioshock made FPS's good.

Timewise: Mario Kart Wii

Emotionwise: Super Mario Galaxy

Nintendogs and BioShock