Twenty years, in terms of horror films, doesn’t sound all that long. Yet it adds up to a generation, and the list below reflects that. It’s a catalog of the cinematic fears and obsessions that define an era. The list is also destined to start a few fights (no, I’m not a fan of “It Follows,” and yes, I do think “What Lies Beneath” is that good). So feel free to object, and to point out the dozens of terrific films I left out.

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20. The Babadook (2014)

It’s scrappy and, at times, a little short on atmosphere, but Jennifer Kent’s sinister maternal psychodrama puts you inside the head of a woman on the verge like no horror film since “Repulsion.” It’s set in Australia, where Amelia (Essie Davis) was widowed in a car crash the night she gave birth to her son (Noah Wiseman), who is now six. (Her husband was driving.) The son is deeply troubled, but not nearly so much as his mother, who’s plagued by visions of a character out of one of his illustrated storybooks — the Babadook, a walking-cutout Dr. Caligari crossed with Jack the Ripper who seems to be expressing nothing so much as her own forbidden rage. It’s no wonder he’s terrifying.

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19. Drag Me to Hell (2009)

Director Sam Raimi orchestrates a tongue-in-cheek symphony of fear in this grippingly baroque gross-out of a thriller about an innocent young bank worker (Alison Lohman) cursed by a decrepit, one-eyed gypsy woman (Loran Raver) to whom she denied a loan. This is the Raimi of the “Evil Dead” films, the Grand Guignol prankster who gets us laughing at our propensity to be shocked, then just keeps upping the ante. Only now Raimi is working in the digital era, which he takes full advantage of with insanely eruptive imagery that redefines the phrase “in your face.”

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18. The Witch (2015)

Robert Eggers’ grisly supernatural morality play is set in 1630s New England — and yes, it’s a spectral variation on “The Crucible,” with thee-and-thou characters trapped in their puritan propriety. But it’s also a suspenseful plunge into the abyss. In an early scene, a woodland witch — ancient, nude, evil — murders the infant child of a farm family, coating herself in its bloody remains. The family, led by a father (Ralph Ineson) so pious he protesteth too much, has abandoned the plantation community they were living in, and the disappearance of their newborn kicks off a downward spiral that seems to fulfill some unspeakable destiny. Anya Taylor-Joy, as the teenage daughter who’s accused of witchcraft herself, takes a good role and acts the holy hell out of it.

17. The Human Centipede 2 (Full Sequence) (2011)

Not for the squeamish? This one’s barely suitable for the non-squeamish. In fact, I humbly apologize for putting it on the list. Yet if Tom Six’s sequel to his royally revolting 2009 spectacle of bodily horror is a film that would have the Marquis de Sade gagging into his popcorn, there’s no denying this is one sick-joke nightmare that pushes its snuff scenario to such an extreme that it achieves a certain horrifying catharsis. It’s shot in industrial black-and-white and stars Laurence R. Harvey as a nerdish sweat hog of a garage attendant, wielding a staple gun, who assembles 10 victims, bringing them to a fetid London warehouse to create the ultimate human daisy chain of sadistic depravity.

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16. Paranormal Activity 3 (2011)

Starting in 2007, the “Paranormal Activity” films were the planted-camera successors to “The Blair Witch Project,” and though the whole found-footage aspect was already starting to wear thin, the movies were strikingly effective as gothic suburban ghost fantasies that used the twitchy time-code graininess of surveillance footage to coax our eyes into believing that we might be catching an honest glimpse of the supernatural. The first film was the most original, but this one, directed by Ariel Schulman and Henry Joost (“Catfish”), has the most memorable scares. It’s a movie in which a pristine kitchen starts to look like a torture chamber, and where we’re haunted at every turn by the film’s ominous promise to put a face on evil.

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15. The Descent (2005)

Just as anyone with a fear of heights should probably steer clear of rock-climbing, those with a fear of enclosed spaces will want to avoid seeing Neil Marshall’s finely crafted British shocker about a group of women who go spelunking (i.e., exploring underground caves), wedging themselves into a series of damp rocky crawl spaces. As it turns out, there are monsters in the offing, but oddly enough they’re not the most unsettling part of the movie. That would be the drop-dead claustrophobia, evoked with frightful finesse.

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14. Let Me In (2010)

It’s part of the catechism of contempo horror that the 2008 Swedish cult vampire film “Let the Right One In” is some sort of masterpiece. Sorry, but I think it’s a slipshod and pious movie. The American remake, directed by Matt Reeves, turns the material more dangerous by drawing us into a queasy sympathy with the ambiguous guardian — played here by Richard Jenkins — of a 12-year-old vampire (Chloë Grace Moretz), even though he’s really her slave. That makes Moretz’ youthful blood fiend a far more ironic savior when she befriends a sensitive boy (Kodi Smit-McPhee) in her apartment complex. The bloodsucker scenes are disquieting in a herky-jerky way, and the central relationship is presented as a love so haunted you’re not sure if it will lead to anything but more evil.

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13. A Quiet Place (2018)

John Krasinki’s alien-beasties-in-the-cornfield thriller delivers a weirdly silent and goofy-sinister B-movie bang. The movie tells the story of a family, led by Krasinki and Emily Blunt, who are under siege. To survive, they have to follow one abiding law of safety: If anyone makes a sound — virtually any sound at all — that person will be a goner. A skeletal creature with crab-like pincers and a head like a metallic melon will burst out of the woods to make mincemeat of the noise-maker. The movie is a tautly original genre-bending exercise that generates free-floating dread out of the fact that almost any sound a character makes is potentially deadly. And though the logic works better the less you think about it, Krasinski is a gifted enough filmmaker to paper over our objections. He directs with all his senses.

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12. Planet Terror (2007)

You could call the Robert Rodriguez half of “Grindhouse” a parody and you’d be correct. Yet this riff on a deliciously bottom-of-the-barrel 1980s crawling-slime zombie thriller is made with such heightened fanboy exactitude, and such a poker-faced affection for everything that defined the walking-dead splatter schlock of the time, that you rarely catch the satire showing. Rodriguez has made a memorable homage to that place where horror and cheesiness fuse and become one.

Omega/Kadokawa/Kobal/REX/Shutter

11. Ringu (1998)

The defining J-horror film, Hideo Nakata’s shivery tale was once a cutting-edge fable that merged mossy Victorian return-of-the-repressed ghost imagery with the staticky jolts of 21st-century technology. It now looks like a period piece (it’s about that creaky old thing, a videotape), but what hasn’t dated is Nakata’s vision of how the wormy surrealist imagery of nightmares will always find a new place to roost. The film’s chronicle of unfathomable abuse touches a raw nerve of fear, and though the 2002 American remake was surprisingly well-done, it’s nowhere near as freaky as the original.

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10. Insidious (2010)

Director James Wan casts a major shadow over the horror cinema of our era. He inaugurated the torture-porn genre with “Saw” (2004), and he infused don’t-go-in-the-attic clichés with new energy (though he couldn’t completely transcend their musty aspect) with “The Conjuring” (2013). Yet “Insidious” remains his most artful and accomplished spook show. In form, it’s a good old haunted-house movie, but Wan reaches back to imagery from the 1962 oddball classic “Carnival of Souls” to conjure a vision of the afterlife that’s frighteningly present tense, with ghosts who have a way of showing up to display their hideous smiling faces at just the right moment to leave you drenched with anxiety.

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9. Shaun of the Dead (2004)

There has often been a comic element to zombie films, even if it’s off-screen. (The scenarios are so over-the-top that at certain points it’s hard not to giggle.) Edgar Wright’s cheeky zombie bash plays off that fanboy knowingness in a most delectable way, since the joke of the movie is that the dead have risen and are feasting on the living — but in lumpish working-class Britain, everyone is so blitzed, jaded, and drunk that it’s hard to tell the difference. Still Wright’s best film, the movie works beautifully as the very sort of head-splatter spectacle it’s skewering.

Reid Chavis/PalmStar Media/Kobal

8. Hereditary (2018)

It’s a ghost story with séances, crawling ants, and decapitated bodies, yet the scariest thing about Ari Aster’s disturbing maze of a creep show is how staggeringly personal its demons are. Toni Collette, as a woman fighting off the destructive legacy of her late mother, gives a horror-film performance worthy of mid-period Ingmar Bergman, and Aster directs without any of the usual megaplex-horror razzmatazz. He strikes a tone of exploratory eeriness that’s spellbound with dismay, creating echoes of “Rosemary’s Baby” and “The Wicker Man” that culminate in a finale that will leave you floored. It depicts the forces of the afterlife engaged in an all-out takeover of the here and now.

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7. World War Z (2013)

In 2002, Danny Boyle’s “28 Days Later” rebooted the zombie genre, giving it ferocious new blood. It has attained fresh heights ever since: the epic horror of “The Walking Dead,” the raw desolation of “28 Weeks Later,” a sequel even more chilling than the first film. Yet I’d argue that “World War Z” — a big-budget, big-studio Brad Pitt movie — remains the genre’s most exciting 21st-century spawn. It’s a film of apocalyptic grandeur and seething suspense, and Pitt grounds the story with a dread-ridden command. The slow-burn final sequence, set at a World Health Organization facility outside Wales, was famously added during reshoots, but set aside your prejudice about studios using test screenings to figure out how to end their films and you’ll see that it’s the most breathless and accomplished zombie showdown since the glory days of George A. Romero.

Raw Nerve/Screen Gems/Lionsgate/

6. Hostel: Part II (2007)

Torture-porn movies get no respect, and I’m one of the legions who give them none. Ninety-nine percent of the genre is despicable sadomasochistic trash. But Eli Roth’s ghoulishly shocking sequel to his 2005 torture-porn trifle isn’t just an extraordinary horror film. There’s a weirdly compelling morality to it, rooted in the chilling plausibility of the scenario it presents. Set in a remote warehouse in a Slovak village, where wealthy clients pay for the “right” to torture and kill someone, it’s a global nightmare for the age of websites like Silk Road, and you literally watch it with the thought, “Could this actually be happening somewhere?” Roth has made a movie that’s unstinting in its gore yet looks just like what it would look like if amateurs got to give in to their heart of darkness.

Francois Duhamel/Image Movers/Dr

5. What Lies Beneath (2000)

It sounds like an oxymoron: a Hollywood supernatural thriller, starring people like Harrison Ford and Michelle Pfeiffer, that’s supple enough in its sleight-of-hand terror to get as far under your skin as the most artful indie creep-out. Yet that’s just what Robert Zemeckis’s movie brings off. It lifts elements from Hitchcock films like “Rear Window” and “Suspicion,” telling the story of a Vermont housewife who thinks her neighbor may have been killed, yet Zemeckis lends the tale a dreamy dread all his own; he leads you to places you don’t think he’s going. Pfeiffer acts with a tremulous conviction, bringing this gothic an unusual emotional rootedness, and as for Harrison Ford, let’s just say that his sluggish underacting is, for once, to the point. The final bathtub scene is shivery bliss.

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4. The Sixth Sense (1999)

Let’s give credit to M. Night Shyamalan. His name, for a while, became a punchline (the guy with the twist endings), but he has made a handful of highly watchable movies, like “The Village” and “Split,” along with one that’s amazing (“Unbreakable” — not on this list because it’s not a horror film). But the movie that planted him on the map is still his most restrained and relatable and perfectly proportioned, an elegantly original ghost story with a twist that earns every inch of its “Whoa!” factor. Haley Joel Osment is innocently creepy as a kid who sees dead people, and Bruce Willis is furtive and touching as the lost soul he befriends.

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3. The Blair Witch Project (1999)

Maybe you loved it; maybe you hated it. You certainly saw it, because in the summer of 1999, the original found-footage verité horror movie changed the rules for what a fright film could be. Yet its artistry was about more than novelty. For those of us who watched “Blair Witch” in jitters, it caught something no movie had before — not just the darkness but genuine godforsaken night, and the spirits that run loose in it. A raggedy home-movie descent that plays like a demon version of MTV’s “Road Rules,” this tale of three student filmmakers who get lost in the woods while searching for the legendary Blair Witch now looks like a cautionary myth for the digital age. It says: Just because you’ve got the camera pointed at yourself doesn’t mean they’re not watching you.

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2. Audition (1999)

It’s not (quite) the greatest film on this list, but it’s the most sheerly horrifying — and, indeed, one of the most horrifying movies ever made. Prepare to have your sleep disturbed. Takashi Miike’s bravura bad dream is also a cosmic expression of our age, a tale of feminine wrath and vengeance slashing away at an entrenched system of male control. Think “Psycho” for the age of womanly empowerment. A lonely widower (Ryo Ishibashi) arranges to “audition” women for a movie (he’s really looking for a wife). He meets Asami (Eihi Shiina), a passive and seductive mystery girl, who acts out her damage by putting men through the tortures of the damned. Every era gets the vision of hell it deserves. This one is ours.

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1. Get Out (2017)

A horror movie that’s a true classic should have many elements. It should scare us. It should haunt us (a very different thing). It should lure us in with an emotional and dramatic engagement that transcends mere sensation. It should feel like an ominous dream linked to the society that gave rise to it. That’s what movies like “Rosemary’s Baby” and “Invasion of the Body Snatchers” and “The Silence of the Lambs” do. And that’s the bar that Jordan Peele’s dizzying racial nightmare sets for itself and sails over. “Get Out” dives into the psychology of African-American experience, yet it’s no liberal message movie; one of its cosmic jokes is that liberals are part of the problem. Daniel Kaluuya, as a photographer who travels upstate with his white girlfriend (Allison Williams) to meet her “enlightened” family, roots this tale of terror in an all-too-plausible daily paranoia. It’s like a Polanski film written by James Baldwin, with a sense of menace caught somewhere between the Twilight Zone and “F— the Police.” The result is an indelible roller-coaster of dread, as well as a definitive projection of what it looks and feels like, in that sunken place, when black lives don’t matter.