Alien: The Director’s Cut (1979/2003, dir. Ridley Scott)

The 2003 re-edit (actually shorter than the 1979 original version) reinstates some scenes, clarifies some plot and character points and removes others (Ash is no longer a recent crew addition, and so the conspiracy element is toned down). By no means essential, but a chance to marvel again at this still-influential movie.

Prometheus (2012, dir. Ridley Scott)

Archaeologists lead a space mission to the creators of life on Earth. Good-looking and packed with great images, this Alien prequel is nevertheless hugely flawed, not least with an abundance of intelligent beings doing really dumb things.