Alien (1979)

A commercial space ship towing 20 million tons of ore is on its way home to Earth when it receives a transmission to interrupt its journey and investigate a mysterious signal from a planet. While investigating the signal, one of the group (John Hurt) discovers a massive cavern which hosts a field of large eggs when one of them bursts and a creature attaches itself to his face. The terror escalates when the creature morphs into something more horrible and more powerful than they ever imagined. Directed by Ridley Scott, whose commercial breakthrough this film was, this is one of the greatest horror (despite it's sci-fi setting, it's undeniably a horror film) films of all time. There's no way to describe the impact this film had on audiences seeing it for the first time and the "chest burster" scene ranks with the shower murder in PSYCHO as one of the most shocking sequences of the horror genre. Scott slowly and carefully builds up the tension and increases it in doses as the film reaches its nail biting climax. The awesome art direction and set design is by Michael Seymour, Roger Christian and Leslie Dilley, the intense score by Jerry Goldsmith. With a perfect cast that includes Sigourney Weaver (in her breakthrough role) as the first of the modern action film heroines, Tom Skerritt, Veronica Cartwright, Ian Holm, Harry Dean Stanton and Yaphet Kotto.