Its been probably about 4 years since ive built the computer than im currently using, and it works just fine for the work i do on it, but I have a feeling its not much of a gaming machine anymore. First ill list my basic setup:

athlon xp 2600+ (overclocked to around 3200+ specs)
1GB ddr pc3200
motherboard - Abit NF7S v2
radeon 9800 pro 128mb

LIke i said, i havent done any gaming in a while, but id like to get the Orange Box and be able to play the games and a decent framerate, maybe a couple other games as well.

I havent really even looked at video cards at such a long time, i dont know whats good anymore, or if i can even get a decent card still for my AGP system. I was looking on pricewatch but im getting a little confused as im not familiar with most of the model numbers and such. I dont want to spend to much, but what could i get for around $100 (give or take) that would be an improvement over what i have?

Thanks in advance.