Genji: Days of the blades. This was the first game I played in this generation and I still own it to this day because ever since I experienced the real time weapon change I knew this generation was going to be the most innovative since the NES.

Demon's Souls. Man, that game was a surprise.

Definitely Oblivion.

I bought the game, sunk about 10 hours in and than gave up. I figured it just wasn't for me.

Later on I decided to try it again and for some reason I got incredibly hooked and next thing I knew I logged 120 hours into the game without even going to Kvatch for the first gate.

Before that game I wouldn't touch open world First-Person RPGs and thanks to Oblivion and later on Fallout 3 I believe I found a love for them along with my JRPGs.

Saints Row. The reason being it that the first Next Gen game i got. And even though its not a graphical powerhouse the details in everything amazed me.

infamous, i got hooked to the story the game play amazing. overall ny favorite game and the best game i ever played

Uncharted: Drakes Fortune made me see the quality this generation had to offer.
Call of Duty 4 (PC) restored my faith in FPS as a story telling platform.
Killzone 2 made me love FPS on the console (No clue what everyone bitched about but conversely, I hated CoD 4's controls on console).

OH... and Bioshock (PC). That game just reeked of atmosphere.

mgs4 and uncharted on the ps3. gears of war and halo on the xbox360.

Kirby's Canvas Curse - Showed me the DS was more than a mere novelty and could produce truly fun and innovating games.

Osu! Tadake! Ouendan! - Showed me I could be addicted to a music/rhythm game and the music genre could branch off beyond just DDR/Guitar Hero clones.

Muramasa: The Demon Blade - Finally brought back that love for old school games and Action/Platformers I've been craving since Symphony of the Night. And improved on the style of gameplay and presentation dramatically.

Super Mario Galaxy - Made me actually like 3D Mario games and showed great promise for the Wii to come.

Company of Heroes - Added numerous innovations to the RTS genre that I've been waiting for since the days of Warcraft and Starcraft and evolved gameplay beyond simple 'micro' and 'farming for minerals'.

lost odyssey is another example of a game that made love the jrpg/rpg genre so damn much more.

NSMBWii... It was like Super Mario Bros 3, 20 years later.

The best thing is that the next 2d Mario will be Wii's (or Wii 2's) Super Mario World, 20 years later, and I cannot wait enough for it.

But I have a feeling this next Zelda will be THE game of the generation, just like Ocarina of Time was in its gen.