Radeon 9600 works.
About 70 bucks.
Have it, no lag for me.
Actually because it's the cheapest and best AGP card there is. I'd say it pwns a Geforce 5 seeing as the core clock is also twice better.
55 bucks with rebate.
Sorry for the paragraph every sentence, here's the card:
http://www.newegg.com/Product/Produc...82E16814102600.