Alien

With Alien, Ridley Scott delivered more than just a memorable 'haunted house in space' campfire tale. He and screenwriter Dan O'Bannon used the monster as a Freudian symbol, launched a franchise that lasted for more than 20 years and set the unknown Sigourney Weaver en route to stardom. The crew of the mining vessel Nostromo investigate a distress signal from another ship - but realise too late that it's in fact a warning to stay away. They uncover a huge store of eggs discovered alongside the body of an unidentified alien.

From here, it's a rollercoaster ride of goo-spewing androids, chest-rupturing horror and monster cat-and-mouse, until only Ripley remains to battle the 'bitch' that has used the vessel as a nest for her vicious spawn. Superb performances add to Scott's stylish direction. And if a film can be judged by the amount of rip-offs it generates, Alien must rank as one of the most influential movies ever.