The series has delivered a horror masterwork, a seminal shoot-em-up and some auteurist gems ... but how do they rank?

What better way to celebrate the recent Alien Day than to place the eight movies in the long-running space saga into some kind of order of excellence? And also perhaps to ask how so many film-makers have managed to muck up the original film’s formula.

Let’s start at the bottom. The two Alien vs Predator movies from 2004 and 2007 are now remembered largely for their staggering blandness, as if everybody involved had forgotten what made the early films so chilling. Ostensibly B-movies, but lacking the joyful, half-cocked knockabout bombast of a Roger Corman or Ray Kellogg film, they even disappointed fans of the crossover comic books that spawned them. If 20th Century Fox thought it was getting the new Ridley Scott when the studio hired Paul WS Anderson to direct ’s Alien vs Predator they were sadly mistaken. Bringing the xenomorphs to Earth, as Fox had intended to do in 1992 prior to David Fincher’s Alien 3, turned out to be the dumbest move since John Hurt decided to take a closer peek at the funny egg thing on LV-426. Even a smart moment of stunt-casting – Aliens’ Lance Henriksen as Charles Bishop Weyland – couldn’t paper over the cracks of this weirdly bloodless film. Aliens vs Predator: Requiem upped the gore but dropped quality levels even further, with untried music video directors Colin and Greg Strause at the helm. That the saga survived at all after this twin descent into movie purgatory is remarkable in itself.