Thanks Ananan. I think I'll just buy that 7600gt card. I don't think it's worth it to upgrade my entire system. Since I only play games once in a while.
I'm going to look into overclocking my CPU as well. I've had it for 2 years, but never tried it. I better browse the overclock seciton of this forum or I'll do something stupid and make it explode. Anyway it's a AMD Athlon 64 3000+ Venice 1.8GHz which is decent I suppose