5. Dean Foods ( DF) is the leading processor and distributor in the U.S. dairy market (with sales about five times as large as the second-biggest competitor's). Recently, higher commodity costs and competition have displaced its dairy segment. According to Morningstar, many consumers traded down to private-label dairy during the recession and haven't returned to brand-name products. Dean is engaging in extreme cost-cutting and pricing strategies to protect profitability while regaining customers. A sizable debt load, with a debt-to-equity ratio of 2.7, and narrow operating margin, at just 3.3%, are obvious negatives. But, investors have abandoned Dean. It is the worst-performing S&P 500 stock of 2010, down 55%. Its cash flow multiple of 2.8 reflects an 80% packaged foods peer discount.