ATI drivers are bawlz. Way to many problems.
If you can wait til next month the GeForce 5 will hit the market and it's promised to own your mom

.
If money is a consideration get the TI4400. You can get the Asus TI4400 for about $200 US and it's a stellar card. The TI4600 is phat but it's 33% more for not that much difference, imo.
Always go Nvidia, hell when you fire up Unreal Tournament it says that it's designed for Nvidia technology. A video card isn't shit w/out a good.... or great driver.
While I hold my opinion in high regard, you may want to have the opinions of the people who really beat the shit out of their hardware, gamers. Check
www.thefiringsquad.com, I've never been disappointed with their recommendations.