IMO, If you can afford it, the Saphire 9800 Pro for $225 is best deal in gaming cards right now. I just ordered one a few days ago myself. If this is too much money, a Radeon 9600 pro is a good choice.
ABIT IS7, P4 2.6C, 512MB Corsair TwinX PC3200LL, Radeon 9500 Pro, Santa Cruz, Antec 1000AMG, TruePower 430watt