Wal-Mart Stores

Fortune 500 rank: 1
2009 profit: $14.3 billion

Wal-Mart lowered prices on everything from TVs to shampoo to woo customers in the downturn. Because of its price cuts, the retailer managed to turn a profit amid the recession and gain more loyal shoppers.

In the company's 2009 annual report, CEO Michael Duke writes, "We have so much to be proud of at Wal-Mart when it comes to last year's financial results."

Reference: http://money.cnn.com/galleries/2010/fortune/1004/gallery.fortune500_mostprofitable.fortune/3.html