Out of them, Abit, but you may want to disregard the the AV8, as it has a couple of problems, but if you are lucky, and get a good one, they are extremly good.
MSI neo2 Platinum is a very good overclocker - for agp, so I would consider that one.
The best motherboards come from DFI now, but you will have to wait for agp, but the pci express ones are out now, and are well worth the money.