Dell Inspiron XPS Gen 2
click here <- hope the link works!
Even a mighty 6800Ultra can not play ALL current games on full settings... Everquest 2 springs to mind as a game that looks amazing on a 6800Ultra on Med/High settings, but drops to a crawl on Max settings.
But for the vast majority of games they can be played at 1280x1024 max detail, or 1600x1200 max, or close to max detail.
I have an overclocked 6800GT in my desktop machine and it flies in everything I have chucked at it. Half Life 2 at 1600x1200, Doom 3 at 1280x1024, World of Warcraft 1600x1200, Everquest 2 at 1280x1024 medium detail.