most stable/smooth running mobo for vista?

[sadffffff]

Looking to get a new processor/mobo for my GF. Its likely to be AMD based simply because core 2 duo + mobo is just a little too pricey for me. But lets say I can do either a core 2 duo or amd x2. Which would be the best mobo stability/smoothness wise for each? overclocking and gaming arent a concern here. an onboard video solution that can handle aero is needed, otherwise its going to need an agp slot, or im going to have to also spring for a cheapie PCI-E video card for aero