2. Louise Fletcher Nurse Retched in One Flew Over the Cuckoos Nest
Not exactly one of the most celebrated thespians on this list, but it was one I felt compelled to include. Whilst Jack Nicholson delivers one of his many sublime performances in his career, Nurse Retched is the character that haunted me after watching this film for the first time. Louise Fletcher finds the perfect balance of Nurse Retcheds perceived niceness while actually being cold, manipulative, and inhibiting vulnerable minds with imprisonment in her mental institution. After getting call backs to audition for the role over a period of six months, she went on to win the Academy Award for Best Actress.