7. Jack Nicholson
Jack Nicholson has such an extraordinary knack for playing crazy characters that it's no surprise people wonder about the man himself and where it all comes from. Whether it's his turn as murderous author Jack Torrance in The Shining, his role as The Joker in Tim Burton's Batman, or his turn as wily, psychotic gangster Frank Costello in The Departed, there's that constant feeling that Jack just might be playing himself. So much of his real-life persona seems as manically energetic as his screen ones that it would be very easy for the two to bleed into one another. And where's the evidence? In 1994, a 56-year-old Nicholson, after being cut off in traffic, stopped his car at a red light, pulled out a golf club and smashed the offending motorist's windshield in. This helped cultivate his image as a real-life maniac, something exacerbated by the fact that whenever he attends LA Lakers basketball games, he finds himself screaming at the referees, and has nearly had himself ejected as a result.