One Flew Over the Cuckoo's Nest (1975)

Jack Nicholson plays McMurphy, a recurring criminal who finds himself in jail once again. Rather than spend his time in jail, he tries to convince the guards he is mentally insane so he doesn’t have to spend another stint of jail time. In the mental hospital, he befriends some of the patients and emerges as a leader. Nurse Ratched, a merciless nurse in charge of the patients, is threatened by his attempts to get through to the other patients. He tries to liven up the place but she is constantly on his back. In an unlikely setting, McMurphy befriends the patients and even helps to improve their conditions. One Flew Over the Cuckoo's Nest won all of the "Big Five" Academy Awards at the 48th Oscar ceremony.

http://www.imdb.com/title/tt0073486/