It depends how cheap you're talking. Obviously you'll want to go with a trusted brand (Gigabyte, MSI, Asus, and Abit are a few general ones). These will, of course, cost you more. Other features include ram transfer speeds, but these are determined by the chipset. For example, nForce boards have a faster memory transfer than other ones do and are actually pretty reasonably priced. You could check out one of those, as they also allow for overclocking.