Spore
Starcraft 2
Left4Dead
Metroid Prime 3: Corruption
Super Mario Galaxy
MS4
BioShock
Diablo 3
The Orange Box (All 3 games)
Final Fantasy 13
I never thuoght Halo, Gears, or CoD were anything special. Fun games but nothing really WOW. Gears' co-op was fun but it was done a while ago with Halo. Team Fortress is just more fun than CoD and it came packaged in with Portal and Half-Life2. Halo, both games, this generation is just overrated mediocrity. GAIV was just another iteration on GTAIII so it didn't come close to the WOW feeling III had. This is as far as I can tell so far the best ones listed.
There are 4 games that haven't come out yet, but I'm willing to bet my limbs and my nuts that Diablo 3 and Starcraft 2 will automatically be 90+ on metacritic along with Left4Dead, if not 95+. Valve and Blizzard have NEVER failed to deliver, not once. Also every game they come out with revolutionizes gaming and brings new things to the table in one way or another. There's no chance they won't be some of the best games this generation, most probably the best (They do cover the RTS,RPG,and FPS genres). Final Fantasy 13 is also a pretty surefire thing, but you never know, SE has made mistakes.