I use a x800xt PE with Omega modded drivers.
These are not "official" drivers but do provide the best image quality for my system (everyone's is a little different).
For Omega Drivers try here at:
http://www.omegadrivers.net/
Another reason to avoid stock drivers is they (ATi) are forcing people to have to use the CCC panel system which requires .Net and is a lot of tax on your resources.
Omega are basic ATi (no CCC) with tweaks to setting made by the author
g/l <g>