In 1963, in Haddonfield, Illinois, the six-year-old Michael Myers stabs his sister to death in the Halloween night and is confined in a mental institution. In 1978, Michael Myers flees from the institution on the Halloween Eve carjacking his psychiatrist Dr. Samuel Loomis (Donald Pleasence) and heading to his hometown. On the next morning, Michael stalks the high school student and babysitter Laurie Strode (Jamie Lee Curtis) that has a sixth sense that is followed. However, her best friends Annie Brackett (Nancy Loomis) and Lynda Van der Kiok (P.J. Soles) mock her. Meanwhile Dr. Loomis arrives in Haddonfield looking for his patient.
John Carpenter's "Halloween" is maybe the most successful slasher of the cinema history tha became a classic. With the budget of only US$ 320,000, this film surprised with the world with about 47 million-dollar box office only in USA and introducing Jamie Lee Curtis to her fans. Further the franchise, remake, video game, toys, and many other attractions. My vote is seven.
Title (Brazil): "Halloween: A Noite do Terror" ("Halloween: The Night of Horror")