What is the scariest science fiction or fantasy film of all time? Which movies stand above the rest off all horror flicks as the most terrifying?

The staff at io9 has painstakingly selected the best of the best, and compiled our ultimate list of the scariest movies of all time. Over the next few days we'll be releasing our picks, ten at a time. Yesterday you saw the first 10 out of the 50, today, check out numbers 40 through 31...

40. The Cabinet of Dr. Caligari (1920)
What: An extremely creepy silent film made in Germany using sets and makeup influenced by expressionist paintings like Eduard Munch's The Scream. Think twisted houses, bizarre masklike faces, and streets that zigzag to nowhere. Into this crazytown comes the showman Dr. Caligari and his "somnambulist" (sleepwalking) servant Cesare, who prophesies people's deaths during a show — and kills them later. Francis and his beloved Jane are the only ones onto the doctor's nefarious plot. Can they stop the doctor and his zombie-esque servant before more people die?
Why: Not only is this movie insanely disturbing, but it also has what many historians call the first twist ending in cinema. Hell no - we won't give away 91-year-old spoilers! You can watch the whole movie for yourself right here - it's only 51 minutes long.
Scariest Scene: When Cesare predicts the death of Francis' friend Alan.

39. Hellraiser (1987)
What: A very bad man named Frank finds a strange puzzle box which unlocks the a parallel universe of carnal pleasures so intense it goes beyond pain. He's immediately chained up and ripped into bits. Later on Frank's brother moves his family into Frank's seemingly vacant family home. Their presence awakens the skin bits of Frank and his slimy body returns back from his parallel prison. Still weak Frank convinces his sister-in-law to lure unsuspecting men back so he can feast on their bodies and regain his strength. It doesn't go well for this family and the Cenobites return looking for both Frank and some new playtime pals.
Why: Clive Barker's Hellraiser flicks raised the bar on gore. This movie is awash with fake flesh, blood and filthy deeds. But perhaps the biggest success from Hellraiser was creating the regal creature that would later be named Pinhead and his horrifying collection of creatures. The Cenobites are horrifying, even in the one in sunglasses.
Scariest Scene: The first ever Cenobite reveal.
38. Frankenstein (1931)
What: Cobbled together from pieces of the dead Dr. Frankenstein reanimates a giant monster man, with unimaginable strength.
Why: James Whale's recreation of Mary Shelley's "science run amok" story set monster movie standards. Boris Karloff's brow became the infamous face of the monster, Dr. Frankenstein's creation shrieks have been copied and recreated thousands of times, and it solidified the precarious relationship humans would always have with the beasts of the night. You feel for the Monster when it plunges the village girl in the lake, but at the end of the day he's still made up from the leftover bits in the graveyard. Pitchforks at the ready.
Scariest Scene: "It's alive! Alive!"
37. Dawn of the Dead (1978)
What: George Romero's sequel to Night of the Living Dead, the touchstone "zombie as a metaphor for brainless consumer" narrative.
Why: The blue make-up and slapstick humor of Dawn of the Dead may not freak out audiences in 2011, but the film pioneered the idea that, during the zombie apocalypse, any public building can become a mausoleum. Also, DotD aptly illustrated the dangers of zombies in massive hordes and how dangerous our fellow humans can be once society goes to pot.
Scariest Scene: Certainly not the ending, which turns from creepy to hilarious in the heartbeat. (Incidentally, the ending was supposed to be a lot more depressing). For good scares, try the apartment chaos at the film's beginning, the scene where Roger finally dies (left), and when the bikers' antics turn deadly. Also, the band Goblin's theme to the film is 100% aural dread.
36. Rosemary's Baby (1968)
What: A happy young couple finds the perfect New York apartment with the cutest little Satan worshiping neighbors.
Why: Roman Polanski loves to play around with your blind spot. The whole movie is set from Rosemary's POV, so the audience never really knows who's on her team and who's a secret devil worshiping cult member hell bent on getting their lord's seed inside her womb. It's horrible watching poor Mia Farrow's health and sanity slowly slip away. And this is after she's raped by Old Scratch.
Scariest Scene: Many folks praise the Lucifer love scene as truly frightening, and that's all well and scary. But nothing tops a room full of retired folks toasting with a loud, "HAIL SATAN."
35. Drag Me To Hell (2009)
What: A pretty young lady denies an old Gypsy's loan request. The Gypsy curses her to hell.
Why: So much classic Sam Raimi crazy in this movie from a talking goat to a very bloody kitty sacrifice. And when Drag Me To Hell isn't throwing wrinkly gypsies at the audience's face it's doing everything in it's power to disgust you, everything goes into the poor little heroine's mouth. Dirt, flies, Gypsy vomit, fingers her mouth becomes a waste bin of ghost farts and Gypsy barf.
Scariest Scene: There's plenty to choose from, even the Gypsies tantrum thrown on the floor of the main character's bank is pretty uncomfortable. But the best, hands down is the pop up surprise in the very last scene. Thus teaching us all a valuable lesson, respect and fear Gypsies.
34. Invasion of the Body Snatchers (1978)
What: Based off the Jack Finney novel, this 70s remake was one of the rare films that upstages its predecessor. Philip Kaufman's creepy FX work paired with Donald Sutherland's paranoia makes this movie unforgettable. An alien race lands in San Francisco and mimics Earth's plants. Then these strange and interesting plants start snatching up human bodies, killing off each host they copy.
Why: First off, there's hardly any jump scares in this flick. Kaufman used plain old paranoia to horrifying the audience. And when he wasn't keeping the audience guessing on which characters was secretly a pod person he threw dog-faced mutants at you.
Scariest Scene: The final reveal.

33. Cloverfield (2008)
What: A Kaiju attacks New York while a pack of twenty-somethings film it from their digital recorder.
Why: J.J. Abrams practically reinvented the found footage genre with this movie. Instead of looking through crappy clips we had sexy shaky came with loads of CG monsters and crystal clear glimpses of the monsters giant pulsing brain sack. Plus the nice thing about this picture was they weren't afraid to kill off plenty of folks, just about every character you meet died by the time this footage was "recovered." And finally there was tons of delightful landmark damage from Columbus Circle, the Brooklyn Bridge to lobbing off the Statue of Liberty's noggin, and that's just classic monster service right there.
Scariest Scene: When the gang retreats into the subway system of NYC they're greeted by a pack of hungry parasites.

32. Predator (1987)
What: 'Arnold Schwarzenegger (known as Dutch) leads his elite special forces team into a jungle in Central America under the guise of rescuing hostages. Meanwhile a warrior alien is dropped off on Earth to collect and clean skull and spine trophies. The "Predator" kills off most of the special forces team leaving Dutch in an excellent showdown of man versus alien beast.
Why: It's a simple fight to the death story that works wonders for keeping it simple. Sure the Predator has lots of spacey doodads like heat vision, a shoulder cannon and an invisibility cloak, but Dutch has two massive arm pythons and a whole lotta boy scout smarts. It's bloody good fun.
Scariest Scene: The final face reveal followed by the classic, "You're one ugly Motherfucker."
31. Candyman (1992)
What: Look in the mirror and say his name 5 times, and the Candyman will come and get you! Seeking revenge for his brutal murder the Candyman stalks the folks of Cabrini–Green. When a young graduate student jokingly invokes the Candyman he appears and begins murdering everyone in her life.
Why: First for taking an urban legend and making it horrifying. Pair that with Tony Todd's spine tingling baritone and all the motherfucking bees. So many bees, they were everywhere, real bees! In Todd's mouth, on Virginia Madsen's hair. The Candyman already had a bloody hook hand, he didn't need an open chest cavity stuffed with bees. But that was what we got.
Scariest Scene: Bee Mouth!

Previously:
io9's 50 Scariest Movies Of All Time 50 - 41