ATi still makes a range of AGP cards, but I don't think they will be making new models, just keep selling what they have.
I would suggest the same as obsidian. A 3850 or a 4670 AGP model. Make sure it is AGP and not PCI.
@xbeater: Quiet a few people still have AGP and don't have the need or want to upgrade. ATi still sells a large number of AGP cards from multiple vendors. How ong they will do it who knows but as long as they are selling as well as they do I oubt they will stop.