The Geforce FX series weren't the best cards to play games. You could better pick an Ati 9600, Ati 9800, X800 or the NVidia 6x00 series.
But don't buy LE, SE versions of these cards. They crippled the memory bus.
A good value for money is buying the Nvidia 6600 GT. It's faster than a Ati Radeon 9800 Pro and 9800 XT. If you don't want to spend around $200, you could buy a 9600 XT.
It's a reasonable card to play games, but don't expect to run at very high resolutions.
