Since the dawn of cinema, viewers have enjoyed the thrill of being terrified by a whole cavalcade of movie monsters - everything from demons, witches, vampires, to creatures from Black Lagoons.
But there has always been something particularly chilling about ghosts.
It's likely we all know someone who has claimed to have seen a ghost before - a friend, a family member - maybe you think you've seen a ghost yourself? Somehow, ghosts remain an elusive phenomena that have never been fully proven to exist, or disproven.
There are old photographs of translucent shapes on stairways, audio recordings of eerie whisperings from graveyards, and whole television shows dedicated to hunting them down in abandoned buildings. It's tough to be a fully fledged sceptic when ghost stories are so ubiquitous. Perhaps that's why we find ghosts a more chilling movie monster than, say, The Blob?
Or maybe the true terror of ghosts is simply that they remind us of our own mortality...
Be they poltergeists flinging objects around kitchens or ghastly apparitions of the undead popping up from the shadows, this list counts down the scariest spectres and foulest phantoms ever to appear on celluloid.
10. Librarian - Ghostbusters (1984)
Despite its title and premise, the movie Ghostbusters is not a horror movie. This classic '80s comedy may seem like a strange place to start when looking at the scariest ghosts in cinema, since no-one is going to be losing much sleep over Slimer or the Stay Puft Man.
These comedy ghouls and Bill Murray’s dry quips are what many viewers remember most from Ghostbusters. But the movie’s opening scene in the library provides a genuine scare.
The librarian ghost appears as a spectral figure of an old lady silently browsing through books. When the ghost-busting gang advances on her, she transforms into a hulking, roaring, skeletal monster.
The humour leading up to the scare, including the ghostly librarian hushing Bill Murray, disarms the viewer before smacking them with the monstrous metamorphosis.
And it works for the movie that the first encounter with a ghost is actually frightening, because if the ghosts weren’t scary, why would anyone bother to call the Ghostbusters?