The 8800GTS 320MB is completely obsolete and cannot be recommended. For your budget, the 9600GT is a good choice, and the 8800GT is a better choice. Both dominate the 8800GTS 320MB in gaming performance.
His budget as he wanted was to be around 150 if possible so i didn't recommend any of this for a purpose, if you compare the 8800GTS to the HD3870 it almost scores the same and beats the HD3850 by a margin you can find this HERE. I was just trying lower his budget as much as possible but however if you can up it a bit then the 8800GT 512Mb is the better choice.
Soorena