I built my system about two years ago and other than the video card fans spinning up whenever I'm looking at flames, the game runs just fine.

EVGA x58 motherboard
Intel Core i7 965
2x Nvidia GTX285 SLI
6GB of 1600DDR3
Asus Xonar DX sound card
WD Caviar Black 1TB hard drive
Blue-ray drives (R and R/W)
Monsoon CPU cooler
Silverstone Fortress tower case
Corsair 1K power supply
Samsung 24" 1920x1200 display (a dying breed *sniff*)
Windows Vista64

Hoping to move to Windows 7 64-bit and perhaps a couple of GTX 580s in early 2011.

Built to play Crysis at ultra settings. Turns out it eats just about everything else for breakfast too, even two years later. And yeah, it was expensive at the time since it was all new tech.