Cool, thanks for all of your advice! However, some of you are suggesting ATi cards.
Isn't that incompatible with my mobo? Or can it handle both ATi and nvidia cards?
If ATi is compatible with my mobo, then is that X1650 Pro Radeon card mentioned by mtyermom a better deal than the 7600 GT since its cheaper?
Also, is a 450 watt PSU good enough for my current rig, plus a new 7600 GT or x1650 card?