6800GT, or the soon to be 6800gs.
Personally, I'd take the 6800gt or gs over the x800 cards just because of shader model 3, but for you maybe you dont want it, in which case i'd just go for whatever fits your budget.
If the 6800gs comes to AGP soon, which it might, I'd wait for that...that'd be the best card for the price without a doubt.