Re: What games can I run?
You could probably run every game except Crysis very well. I *think* the 8600GTS is as good if not better than my x1950pro. I run every game I have (every source game, WoW, BF2142) at max settings @ 1680x1050. I do have to cut down the AA and AF on some of the newer Source games like Portal though. But since your running a lower res, you could probably turn them up a little.
Stacker 830 - e6600 @ 3.6ghz - Eva 9800GTX+
X-Fi Xtrememusic - 4GB OCZ SLI 1066
Sceptre 20.1" - Logitech Z5500 - Gigabyte DS3 965p