I actually have a 9800 pro in my machine right now, and just got finished playing farcry and unreal 2k4 with absolutely no issues at all. For the money, since it seems you are in need of a card, go for it. Mine hasn't let me down.
P4 3.2 GHz Althon 3200+
Asus Mobo Gigabyte Mobo
1 Gig Ram 1 Gig Ram
Ati 9800 Pro Gigabyte 6600GT
250 Gig Maxtor HD 160 Gig WD HD