Im running a GeForce 6600 LE currently and I was wondering if this card is not better, better, way better, or extremely better. Heres the link: http://www.newegg.com/Product/Product.a ... 6814133199
My specs are Amd 2.2 Gig CPU, 1.7 gigs of ram, GeForce 8600 GT. Will I be able to run GMod well? And Will I be able to run Crysis on low settings?

The minimum GPU requirement for Crysis is exactly what you have right now. But obviously it's going to choke along. The card you've picked out would get far better performance though. Gmod shouldn't be a problem either.

I have a 8800 GTS OC. I can run HL2 with 6xAA and 16FA; 1280x1024 and all of the other settings on high settings. The game runs at about 45FPS, also have a Core 2 Duo 1.86ghz and 2GB RAM.

Just as a note, do not worry about your PSU;
A Geforce 6600 GT uses 48w and a Geforce 8600 GT uses 41w accoring to; http://www.extreme.outervision.com/PSUEngine

From what I've heard, a 8800 is infinitely better than a 8600 if you're upgrading. I'd save the extra money and get that.