I'd recommend you to use the DRI driver. I've had great experiences with this driver, although its GL support is somewhat narrow. If a more worthy 3D system is what you want, I'd recommend you to make the upgrades necesseary and go for Schneider Digitals driver or XFree86's own driver, but please give me some feedback if you do.
Now that you've been given the information you need to choose a driver, choose one and move on!