Robert Downey Jr.
Repeatedly arrested in the '90s on drug-related charges, Downey served nearly a year in prison from 1999 to 2000, which forced him to be written out of Ally McBeal
Committed to cleaning up his act, Downey, who's been candid about his troubles and his recovery, revived his career in 2008 with mega-hits Iron Man
and Tropic Thunder
, for which he earned his second Oscar nomination. Now one of the highest-paid actors
, Downey pleaded with Hollywood to forgive his friend Mel Gibson like they did him in his American Cinematheque Award speech in October 2011.