Alien (1979, dir. Ridley Scott)

A commercial space vehicle answers a distress call. Perhaps showing its age in some of its choices, nevertheless Alien is a storming piece of cinema, is outstandingly designed, directed and acted, and remains both relevant and influential 40 years on. A classic.

Aliens (1986, dir. James Cameron)

57 years later, Ellen Ripley faces the xenomorphs again. Superlative sequel, balancing the body horror shocks of the original with military action, suspense, and a then-voguish Vietnam War aftermath aesthetic.