Hmmm. . . I think technically KZ2 has the best numbers (for a console, my PC can't even look at Crysis), but I think artistically it looks like ass. Uncharted 2 has unparalleled animation, and a lovely color palatte. I think that Mass Effect is my favorite looking game, my female Shepard is uncomfortably good-looking.
Upcoming, well you can guess that I think ME2 will be amazing to look at. But I also think Heavy Rain will be somthing to see as well, as far as character models and environments go. Man it's great to be an all-console owner again!