And honestly If you really can, try and get the 6800. I was ordering a 6800gt from newegg, instead they sent me a 6800. Got bored and installed it, and there was a pretty big difference between the 6800 and my 6600gt gamewise. Benchmarks only showed a 1000 point increase. HL2 and CSS defualted to everything high 2xAA and 4xAF at 1280*960 @ 50- 96 Fps, when is was normally everything high and no AA or AF at 1280*960 at 40-80 fps.
Same with Battlefield 2, I was able to raise textures to high, and lighting and dynamic shadows to meduim with 2xAA at 1280*960 running 45-60 fps.
Dont get me wrong the 6600gt is an awsome cards, but the 6800 is just that much better.