The easy answer is any card you can afford. As long as a MB has a PCIe x16 slot, it will run any PCIe x16 gfx card. It doesn't matter if it is PCIe V1.0, 2.0, 3.0... PCIe is a backward compatible interface.
But you may want to be sure you don't spend more on a gfx card than your 1) PSU can handle and 2) than your CPU can keep up with.