Crysis, Far Cry 2 and Just Cause 2 are pretty good as far as graphics go, but I'd like to give a special mention to some other games:
1) Call of Juarez: Bound in Blood
This engine has jaw-dropping textures and bump mapping, and it runs really good on even lower end hardware. IMO, it is the number 1 candidate for most efficient graphics engine.
Check out the screenshots:
*img15.imageshack.us/i/cojbibgamex862009092121.jpg/
*img96.imageshack.us/img96/7921/cojs.jpg
*img406.imageshack.us/img406/1179/coj2d.jpg
2) Tomb Raider: Underworld
Good textures, smooth lighting, great shaders. What else is to say?
*www.tgdb.net/images/full/16-Tomb_Raider_Underworld.jpg
*www.ngohq.com/attachments/games/1213d1225796579-tomb-raider-underworld-pc-demo-tru-2008-11-04-04-51-32-35.jpg
*compresadeadamantium.files.wordpress.com/2009/09/tomb-raider-underworld-20080130053333905.jpg
Other "good" games in terms of artistic direction are Darksiders, Alpha Protocol, Neverwinter Nights 2, the Witcher, etc. but they aren't pure eye candy like these games are