AnandTech has a pretty good review of some budget cards here:
http://www.anandtech.com/video/showdoc.html?i=1933&p=30
You should consider a Ti4200. According to pricegrabber.com, there are a few under $100. If you want the card to last awhile though, I'd suggest waiting awhile and saving $50 to get the ATI Radeon 9600 pro. That's supposed to be a pretty good card.