The ATI Radeon X800GTO (X800GTO2? it's been a long time) was popular (I remember I wanted it so badly but had no money
). You could look around at local computer stores, some might still carry it in stock.
Adlenz, is your motherboard only able to take AGP cards? If so, that limits your choices, but not to worry, they still make plenty of AGP video cards (not as many choices as PCIE though).
The Radeon X1650Pro
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161053
Or the Geforce 7600GS (a bit more pricey)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121064
Btw, newegg has other models based on the X1650 and 7600GS so feel free to look there, I just pulled some that were close to your price range.
There are also some AGP Dx10 cards coming out. I'm not sure of the performance of them, I havn't read up on it. But if you get a DX10 card, it's a good idea to make sure the rest of the system is up to the task of Dx10-level gaming.
Good luck