Uncharted: Both games are simply amazing. It's been said many times before, but Uncharted is like playing a summer action movie. The story might not be mindblowing, but the characters' and their personalities really push the game forward. Plus the fact that the puzzle platforming is fun, and the gunplay is fast and flawless.
Assassin's Creed: Like one else said, AC was a game born for the next gen. The first time you climb a view point and scan the city, you see all the graphical detail that past gen consoles could only dream about. Plus, it used a new and unique controller scheme, instead of just using something tried and true.
No More Heroes: The game doesn't scream next gen. Hell, the game features little tributes to the old days of the 8 bit era. Interestingly enough, both versions seem to go in a different direction. The strength in the first game was the characters and their personalities. Plus, the music was awesome, and those t-shirts you found were pretty cool. Meanwhile, the second game's strength was gameplay, whether it was the improved fighting engine or the new 8bit styled minigames.
Bioshock: I don't like first person shooters. I LOVE Bioshock. Maybe the same reason I like Bioshock is the reason that hardcore FPS fans think it's just good. The game isn't about shooting hordes and hordes of baddies, and having their blood splatter the screen. It's about the environment. The storyline. Frankly, that drew me in. I wanted to explore Rapture and learn about it. The original game let me do just that. The sequel seems to be trying to grab both audiences though. It's a little harder, you can dual wield now, there's multiplayer. They tried to make it more of a FPS player's game. At the same time, they tries to bring back the exploration of the first game. It works just fine, but it's one of those things thats just... it's losing more fans than it's gaining.
Trauma Center: I ain't gonna front, I LOVE Trauma Center. I don't know if it counts because technically it started on the DS but... It's all about the Wii versions. When i first got my Wii, I was pretty disappointed. Wii Sports was too simple. Zelda kinda sucked, and was just a Gamecube game with motion tacked on. Metal Slug was well... Metal Slug. Trauma Center was the only thing on the Wii early on that said "Hey, this motion thing can actually work if they use it right!"
By the end of the year, I'll induct Dead Rising and Valkyria Chronicles into the committee. Unlike RK, I'm not willing to just hand over best series titles to these guys until their sequels (or redemptions in Chop Til You Drop's case) are released.