Everybody knew Robert Downey Jr. was great, but his own self-destructive tendencies got in the way of him fulfilling his promise. Despite great performances in Chaplin and Natural Born Killers it was always his personal life that took the headlines; namely his very public struggle with drug addiction. After being arrested a few times for drug possession, he was finally sentenced to jail time in 1999, where he served one year of a three-year sentence. He quickly got back on the horse, though, when he got landed a role on Ally McBeal and managed to get people tuned into it again. He received rave reviews for his performance, but when he was again busted for drug possession he was fired and considered damaged goods. He found himself all but unemployable for a few years, but after receiving great reviews for Kiss Kiss Bang Bang and other movies Marvel decided to hire him for Iron Man. After that, the rest is history.
