Optimization for my pc spec

[-Dargo-]

Hi everybody, here's my problem: I tried a few games but i'm experiencing lots of problems on graphic side: fps always around 20/25, bad clipping, slowdows during FMVs...
My pc specs:
Intel Core 2 Duo CPU E6550 @ 2.33 GHZ 2.33 GHZ
RAM 2gb, graphic card NVIDIA GEFORCE 8600 GT.

I know it's quite outdated stuff but could you please give me a nice configuration, more performing and lesser "good looking"?

Thank you very much