What do you need from it? Solid 3d performance or not? You can pick up a PCI ATI Radeon, but if you don't really need anything that's great for 3d, you can pick up a PCI Nvidia Riva TNT or TNT 2 for a good price, and if you just need good 2d, the Matrox Millenium is a GREAT card for 2d that you can probably find for nothing.
I'd go with either a PCI Radeon, or a PCI Riva TNT/TNT 2. 3dfx made a PCI Voodoo 4000, but I wouldn't go for that. The Riva would go fine for what you need, as would the Radeon.
That's an AGP card though. red needs a PCI. <a href="http://www.axiontech.com/cgi-local/hardware.asp?category=Video+Adapters&subcategory=PCI">Here's a good list of PCI cards and their prices</a>. The Geforce 2 MX 400 is another option, but I'd go with the Riva TNT/TNT 2 b/c it's a better price, and can do what you need.
