Ridley Scott redefined the sci-fi horror film genre when he directed Alien in 1979.

Not only did he use gorgeous creature design, but he created a strong female lead role in Ellen Ripley (Sigourney Weaver) and he took the whole thing very seriously.

The original concept was created by Dan O’Bannon who wanted to make a movie with a real alien, not just a spray-painted beach ball, and Swiss naturalist HR Giger surpassed all expectations with his scary, surreal drawings.

Computer games, comics, collectable figurines and boxed dvd sets with extra material have all expanded the universe and the alien and its kill methods have been referenced and imitated in movies and programmes the world over.

In addition to the four films, there are also two Aliens vs Predator films, but while their special effects are okay, they pale in comparison to the originals.

Alien (1979): In space, no one can hear you scream, ran the tagline for the first film which was afforded a luxury not many films are allowed nowadays – silence and pacing. Scott makes you wait for that first reveal, and then makes you wait a little more until you are on the edge of your seat, waiting for the characters to be eaten by the monster.

It is first and foremost a horror movie in space – featuring the 14th most recognisable screen villain ever, according to the American Film Institute – but it’s also a thinker’s movie, never sacrificing satisfying cerebral curiosity for a cheap thrill.

Aliens (1986): It took a while for the sequel to be mooted, but bringing James Cameron on board as director changed the focus slightly. His less-is-more camera style won the film an Oscar for visual effects and these aliens not only learn, but show they communicate.

Now we find out there’s a mother queen alien that lays eggs, and the stupid humans have returned to the planet Ripley told them to avoid.

Everything in this one was more – action, intensity, scares, stakes – making it a great sequel.

Aliens 3 (1992): David Fincher (Zodiac) actually backtracks on the success of the first two films with this one, pitting Ripley against the monster when her escape pod crash-lands on a mining world.

While the creature design was expanded, it’s grim and nihilistic and has studio interference written all over it. And then it ends in the chestburst to end all chestbursts. Or so you thought until…

Alien Resurrection (1997): Director Jean-Pierre Jeunet took Joss Whedon’s (yes, he of Avengers) script and made a gory hash of it, but there was still a lot to watch. Ripley gets resurrected, but so does the alien queen, so once again the fight is on.

But, this one is more self-aware with a sly wit and visually it’s great, not overdoing the cgi.