inFamous 2

darksiders

I'd say Metro: Last Light. Underrated mainly because almost no one played it, and it will be forever used only as a spec comparison in software charts.

Project Gotham Racing 4 is another game that still looks great and has amazing weather effects.

God Hates Us All!

I don't like the game but Resident Evil 6 is a great looking game. Batman Arkham City looks great for being open world, though Infamous 2 looks better. Just Cause 2 also looks good like people have mentioned. Lords of Shadow is one of the best looking games this gen.

For PS2 I think Castlevania Lament of Innocence and Legacy of Kain Defiance are two amazing looking games that never get any recognition for how good they look..

I think Lords of Shadow Mirror of Fate is the best looking game on the 3DS. Looks jaw dropping in 3D.

Hard Reset

L.A.Noire on p.c.

Dark Souls

Xenoblade. The game looked really terrible at times, mostly the close ups, however for the most part it was a really beautiful game, that often made me stop just to take in the scenery.