The insane success of Star Wars in 1977 left studios scrambling to get their own science fiction films into the theater. That lead to the dreadful Star Trek: The Motion Picture, but also to the brilliant Alien by director Ridley Scott. The 1979 movie tells the story of a group of seven astronauts in the distant future that wake up prematurely from stasis and discover that a parasitic alien has wound up on their spacecraft. It's a greasy, ugly creature, but it's also incredibly smart and it picks them off one by one until Sigourney Weaver, playing the lone female crew member, blasts it out into open space. If she had any idea what horrors awaited her in the sequels she would have probably blast herself out too.