Ben Bernanke: Chairman of the Federal Reserve

Why We Picked Him: He was using almost every tool in the box--and creating some new ones--in order to stop the economy from falling apart in 2008 and 2009.

Report Card: By all accounts, quantifying Bernanke's success requires proving a negative: the true measurement of his ingenuity isn't how well the economy is doing, but how much worse it could have been if he hadn't acted as he did. He helped to bring the recession to its official end in June 2009, but no one--least of all Bernanke--claims the recovery will be quick and easy. He will continue to oversee U.S. monetary policy for the next few years, as he was nominated by President Obama to a second term as chairman and confirmed by the Senate in January.