Another actor on this list who was friends with the writer Hunter S. Thompson (I use the term friends vaguely it's reported that Thompson played the sounds of a pig being eaten by a bear while shooting at Nicholson's house on his birthday). It's no surprise, then, that Nicholson was also known for his heavy use of drugs including cocaine, LSD and marijuana (alcohol is a given). While filming 1969's Easy Rider (directed by Dennis Hopper) Nicholson puts in a fantastic performance as lawyer and local drunk George Hanson. Not wanting to give any half measures, Nicholson got absolutely wasted on drugs and alcohol while filming. According to Nicholson himself, each time he did a take or an angle, he smoked almost an entire joint as preparation. One particular scene sees character's Wyatt (Peter Fonda) and Billy (Dennis Hopper) introduce Hanson to marijuana, so there's no doubt he was genuinely stoned for the scene (lending it unparalleled authenticity). This preparation clearly worked, however, as Nicholson was nominated for an Academy Award as Best Supporting Actor for his portrayal of Hanson. https://www.youtube.com/watch?v=JgiQPdPUNvs
