Now in my opinion, I believe xbox live is one of the best inventions in gaming since probably tetra, which is basically the foundation of gaming as it was one of the first games ever.
I know a ton of people might disagree with me, but I think Halo 3 is a good game on Xbox because it is challenging when you rank up and start to face better people. However, i believe the best game is, and this is a fact, is Call of Duty 4 and the new 5.
Graphics are everything: I rate them Halo 3: 8 Call of Duty:9.5
Post what your favorite game is and rate it (Xbox live or not-)
I disagree with you when you say graphics are everything, people who say that graphics are the most important are just proving that they don't know what they're talking about. Anyways, I'll give you my favourite games for each platform/console (Just the consoles that I own though):
Nintendo 64 - Super Mario 64 Gamecube - Star Fox: Assault XBox 360 - The Orange Box PC - Day of Defeat Nintendo DS - New Super Mario Bros.
Halo 3 is a good game, yes, but Call of Duty 4 and 5 trump it. I do agree that graphics are important, but not so important that it would sacrifice gameplay. My favorite game for XBL(I don't have alot) would have to be Call of Duty 4. Left 4 Dead demo is really good, cool to play online, check it out.