2. Mel Gibson
Mel Gibson is one of those people who is clearly an extraordinarily talented actor and director, yet can't seem to keep his head straight outside of the game. Not only did he make remarks in a 1991 interview that were perceived as homophobic, but his alcoholism gave way to his infamous anti-semitic rant in 2006 that pretty much derailed his career for good, and the final nail in the coffin was his belligerent series of rants on the phone to his girlfriend Oksana, resulting in several racist and misogynist comments. It seems like every time he opens his mouth, he gets himself in trouble. Though he gave an excellent performance in 2011's The Beaver, Gibson's career in mainstream Hollywood has flopped; his talent agency dropped him following the publication of the aforementioned phone calls, he was replaced for his cameo in The Hangover Part II because at least one cast member (rumoured to be Zach Galafianakis) didn't want to work with him, and his planned film about Vikings has completely stalled. Short of his upcoming cameo in Mad Max: Fury Road, it looks like his career might be dead and buried for good.