Well.. It really depends what you want to do.. If you want to do some serious hard core gaming then your going to need a better graphics card than if your just playing Runescape..
I'm about to build a comp for a friend and we are putting this in it:
EVGA GeForce 8800 GT Video Card - 512MB DDR3, PCI Express 2.0, SLI Ready, (Dual Link) Dual DVI, HDTV, Video Card
Price=160$ USD (from tiger direct)
This is a good video card it will suffice for pretty much any gaming.. It supports directX 10.. If you don't want to spend quite that much I would suggest the same series card but 256MB instead of 512..
Another key thing to check is if your MoBo (motherboard) will support it. For example the above card uses PCI Express 2.0. So, just make sure that you don't end up buying a Video Card that your Mobo doesn't support..
Hope this helps
