Thanks guys, Ill try to finish the rest as soon as I can.

Amazing list. 360 surely does have some phat games.

Finally updated the format for your viewing pleasure! :)

Great list 360 does have the best games.

2 new deserved updates!

Fallout 3: Broken Steel

Bethesda Softworks

05/05/09 US / EU

Join the ranks of the Brotherhood of Steel and rid the Capital Wasteland of the Enclave remnants once and for all. Continues the adventure past the main quest.

Fallout 3: Point Lookout

Bethesda Softworks

23/06/09 US / EU

Fallout 3 -- Point Lookout is the fourth action-packed expansion for Fallout 3.

Explore a massive new swampland area filled with new quests and content.

What do you all think is still missing from the list? Im happy to hear all recommendations.

Nice list left 4 dead is a best shooter

I have some advices:
Replace Bully with Red Faction Guerilla
Add IL-2 Sturmovik: Birds of Prey (It got good reviews and I'm trying to get my hands on it)
Kick out DMC4, Prince of Persia or whatever and add Batman
Replace DiRT with DiRT2
Add NFS: Shift to Best Simulation Racer
Add Shadow Complex, Trials HD and Splosion Man

Castle Crashers- Is Fun

Viva Pinauta Trouble In Paridise- I never played it but looks fun.

Fallout 3- Is So fun i kill evreyone.

Halo 3- Is one of the best games out there.

Think this list needs a proper look over. Although I bet some games still should be there, there are multiple titles released since the last update that should be listed. 

Assassin's Creed 2 - just about everyone who has played AC1 and AC2 will say 2 is better

Alan Wake - surely that is one of the top 5 horror games

Fifa 10 - when you get to sports the list really looks outdated, many of the games like fifa have been surpassed by their sucessors

Shadow Complex - Does the Arcade category need reviewing aswell?