put a new motherboard and video card in my main home computer and it screams (my sons are so jealous)

ABIT motherboard with AMD X2 4800+ processor
2GB PC6400 ram
Geforce 7900GS video card

Overclocked to the max.

I do need to really test it on a game though. The flight sim applications I have are very fast but nothing like a real game to make eye candy. Any recommendations for something that will really dazzle the eyes? (I downloaded some demo war game the other day but all the scenes were dark and smoky) I'd like something that showcases lots of different lighting conditions, killer water, smoke, flame, and shadowing.

Art