Escape From New York (1981, dir. John Carpenter)

An infamous criminal is sent into the island prison of Manhattan to rescue the US President. Defiantly odd post-apocalyptic piece, much happier with its production design and oddball characters than delivering on action/horror. Not quite the film you remember.

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.