Which models have AGP?

A local computer vendor is carrying a number of refurbished Optiplex systems for really good prices. However, I'll need one that will work with my current AGP video card. So what is the oldest model that has an AGP slot? Its hard to tell from the online references at Dell. However, from what I can tell, GX110 models and anything older than that definitely do not.

Note to the mod: This might be good to add to the FAQ as a lot of people seem to ask questions about AGP support.

Thanks!