29: Jamie Dimon

A century ago, J. P. Morgan grew fat by cleaning up Wall Street's messes. In 2008, the trim 52-year-old Harvard M.B.A. who runs JPMorgan Chase feasted on the incompetence and misfortune of others. In March, Dimon picked up failing Bear Stearns at a fire-sale price. In September, he pulled off a similarly shrewd deal for Washington Mutual. Thanks to a combination of pre-emptive work—Dimon's crew simply managed risk better than its rivals—and hard bargaining, JPMorgan Chase emerged from this plague year as the nation's largest bank: 5,410 branches and $2.25 trillion in assets. And Dimon, like his illustrious predecessor, is the financial world's dominant banker.