Graphics cards for designing games?
nVidia Quadro series, 3DLabs WildCat series, ATi FireGL series.
Matrox and Appian also have some models that can be quite useful in some instances due to their extremely good multi-monitor impementation which would be extremely useful for graphics design work.
A specific recommendation is impossible as I've no idea what applications your using, what OS, system configurations, price range. What type of graphics design you will be doing etc.