When Ridley Scott made Alienin 1979, he probably never imagined that it would spawn such a large franchise. The film — about a crew of astronauts who investigate a distress signal from a mysterious planet, only to be attacked by a strange creature — is considered one of the finest sci-fi productions ever made. So far, there have been nine films in the series, each of which has performed fairly well. Out of these, three have been directed by Scott.