A few games, in two categories:
Artsy: (these games I love for their simplicity, but art direction that tries something different and cool)
Rez, ICO, Wander and the Colossus, Lumines, Everyday Shooter, Bioshock, World of Warcraft, Okami
Technical: (More based on being fucking pretty to look at)
World in Conflict (seriously, at 1920x1200 as you gaze out into the rolling sea lit perfectly by the sun...) Gears of War, Bioshock, Metal Gear Solid 2, 3