Upgrade Graphics Card

o_o what PSU do you have?

Also what's you're budget? Since it's a PCI-E board with the Intel 975X you should be able to use any card, ati or nVidia. If you want to take advantage of crossfire support though that would be a bit silly with that old CPU. Anyway, I'd say go with a 6770

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

You could also go with a 6850 if you plan to upgrade soon. Really though it's a bit silly to go with anything more powerful for that system. I recommend you get a 4GB dual channel kit (2x2GB) and get a core 2 duo off ebay or something if you plan to keep that thing for a while. You could also overclock that P4 but of course you need a good tower cooler because they generate alot of heat.

you should really consider upgrading your cpu as even the weakest cards will be bottlenecked by that cpu.

The 6450 would be the most powerful card you need with a p4 since your cpu will not be able to keep up with faster card thus gaining no performance.