6. Wal-Mart Stores
Fortune 500 rank: 1
2010 profit: $16.4 billion
Wal-Mart defended its top spot on the Fortune 500, but it slipped three notches on our list of the most profitable. The cause: recession-weary shoppers. In the depths of the downturn, Wal-Mart slashed prices on everything and attracted American consumers.
Wal-Mart couldn't keep the strategy going in 2010: The company posted U.S. same-store sales declines for the entire year. Dollar store chains and online merchants have eroded some of Wal-Mart's appeal. Its foray into chicer clothes didn't help results either.
NEXT: 7. International Business Machines
Last updated May 10 2011: 8:38 AM ET
