ROBERT DOWNEY JR: The charismatic actor went from cautionary tale to bankable movie star last summer for his performance in the Marvel Studios blockbuster "Iron Man," which grossed $318.3 million domestically. He also got raves for his risk-taking role as an actor in blackface in "Tropic Thunder." Like Rourke, Downey had trouble finding plum roles that exploited the depth of his talent after some personal trouble — and Downey's dark path included a crippling battle with addiction that led to stints in jail and rehab. Now clean, Downey proved he could draw millions to the multiplex last summer as billionaire genius-turned-superhero Tony Stark. That's something new for Downey, who previously acted in smaller-scale movies. And he'll do it again: Marvel has tapped him to star in "Iron Man 2" and "The Avengers," respectively slated for 2010 and 2011.