Stardom came late to Samuel L. Jackson; the loud-ass leading man had been a struggling actor for two decades and was in his 40s before he finally made it in Hollywood. What was he doing before he broke through? Playing bit parts and falling into a drug oblivion that included smoking crack.

After his family got him clean, Jackson drew upon his experiences for his first big role, playing the wildly unpredictable crackhead Gator Purify in Spike Lee's Jungle Fever (1991). The performance won him recognition at Cannes and soon he was on the road to stardom. He now averages over five films a year and is one of the highest grossing actors in Hollywood. This is one crack addiction that actually helped launch a career. Don't tell that to the kids, though.