Well the ATI Catalyst drivers are ALOT better then their old ones.
ATI currently holds the performance crown with the Radeon 9700 Pro and the soon to be released 9800.
Usually with ATI the hardware has been ok, it's just the software is suck, like dwchang said. I had a Xpert98(Rage Pro Turbo). Crappiest card ever! 2D was ok, but 3D just stank. It didn't even support Alpha Blending properly x_X.
Now though, I am looking into getting a Radeon 9100 card to replace my aging GF2

. Since it's cheaper then a GF4 and has near or equal GF4 performance.
Oh and there was also the great Radeon 9500 > 9700 hack that was going around just a few weeks ago. That would have been cool, but I had no money. But it was basically a hack that let you turn a Radeon 9500(which has only 4 working pipelines) into a Radeon 9700(which has 8 working pipelines) which costs 2x the amount of a Radeon 9500 and is about 2x as fast.
ATI isn't half bad now adays.
~klinky