I've got an 8800GTS 320MB, and I'm finding it's chuntering along just fine. I might grab a new one in a couple of months for around a hundred pound or so, but I generally find that spending any more money than that is a waste.
Motherboard: ASUS p5q-pro
Processor: Intel Core 2 Duo - I can't remember of the top of my head, but I think its an E7700. Clock speed is 2.7GHz.
GPU: GPU: XFX GeForce 8800 GTS, 320MB
RAM: 3GB DDR2. I have 2 spare 1 GB sticks from my old PC, but my motherboard won't take them and I've never gotten round to buying more.
HDD: 160GB SATA thing, and an external 160GB USB one. This is all I need really.
Fairly middling. Plays everything thats come out just fine, but I'm not certain it'll play the newest wave of games (MW2, Dragon Age etc) on anything like high graphics. Never know, though.