We're currently enjoying "the best housing affordability conditions in a generation," according to Ron Phipps, president of National Association of Realtors (NAR). Home prices continue to sink and mortgage rates are below 5 percent, setting up a perfect storm for buyers with good credit. Trouble is, many homeowners can't sell their existing home because they owe more on the loan than the home is worth. And tighter lending standards mean first-time buyers are having difficulty obtaining financing.