Best looking game is a bit subjective, what one person see's as being amazing another might see as just another gritty post-apocolyptic world.
I don't believe Gears2 will be the best looking this generation, it'll be up there, but I think there's still more breathing room in the 360 beyond what can be accomplished after 2-3 years (people seem to forget that GoW came out in 2005, 5 years into the life of the PS2 and it was easily the best looking game at that time on the platform and since then has been beaten by other games on the PS2).
Though I believe PS3 will probably come up on top by the end of the generation in terms of technical performance, I'm sure that people will still be wow'd by 360 games for a few more years.
@Krik: Lol, assassin's creed? you cannot be serious. Aside from some nice character models, Assassin's Creed wasn't particularly special. All the graphical proficiency in the world won't save you if there's texture pop-in's, jagged edges , some really ugly textures in certain areas and some poor graphical glitches, which was the case in AC.
Uncharted was much better, though there was some issues, they weren't often or major enough to detract from the experience or change my opinion about the graphics.
I would say the best looking game so far would be CoD4. It's a marvel from a technical standpoint, constant framerate, no screen tears or pop-in's and from an artistic standpoint, it's gritty and extremely realistic (in terms of lighting and architecture). If there was a benchmark, CoD4 would be it, the amount of polish this game has graphically (not to mention the fact that it's multiplatform) make it my yardstick for future games.
