9500 GT is a piece of crap.
9800 GT is a good card (basically an 8800 GT with a new name).
If you buy it from Best Buy I would get one of these:
XFX - NVIDIA GeForce 9600 GT 512MB DDR3 PCI Express Graphics Card - PVT96GYHF4
VisionTek ATI RADEON HD4850 Graphics Card & $10 Gift Card (best deal at the store right now)