I used to have a Biostar iDeq 200N AthlonXP system based on nForce2 that had two VGA connectors, and an Epox SFF AthlonXP nForce2 system that had two VGAs also. I haven't seen anything lately like that, though.
Biostar and Jetway were big on dual onboard video for a while, but I don't know if they're still doing it. Do a search on Newegg for MicroATX boards with onboard video for your best chance of finding something. MicroATX boards mostly tend to have onboard video with the widest choices. NForce based boards all have dual video capability, but the mfgrs choose how many connectors to install. A lot of them just have TV-out riser cables only. I did see a Jetway Socket754 mobo in a quickie search with both a VGA and DVI connector.
My son's Asus Pundit socket 939 SFF system has both VGA and DVI connectors. (NForce 6150-based system). It was pretty cheap, too ($179 a few months ago) and it includes a HSF and decent PSU as well. I'm very pleased with it. The only drawback to that unit is no PCIe slot, only 2 PCI slots, but for it's intended use onboard video is fine. Would make a great HTPC.
I'm not familiar with current Intel-based stuff, though.