JAWS (1975) Directed by Steven Spielberg
''Is it true that most people get attacked by sharks in about three feet of water?'' When this doom-drenched gem the highest-grossing film on our list hit theaters, it gave new meaning to the phrase red tide. Weeks over schedule and dizzyingly over budget, Jaws caused Spielberg more than his share of headaches especially due to his temperamental star. No, not Richard Dreyfuss, but Bruce, the 24-foot-long malfunctioning animatronic great white named after Spielberg's lawyer. ''The fact that the shark didn't work was an artistic blessing in disguise,'' says Spielberg. ''It forced me to be Hitchcockian.'' It's true Jaws is terrifying not for the few times we see the shark treating Amity's vacationers like a Red Lobster smorgasbord, but for those sharkless moments of fear and trembling as we wait for Bruce to feed again.
HALLOWEEN (1978) Directed by John Carpenter
Forget the string of half-baked, nonsensical sequels. Disregard the slew of cruddy, uninspired slasher imitators like Friday the 13th. The original Halloween is, was, and ever shall be the alpha and omega of bogeyman flicks. It also remains one of the most profitable indie films of all time costing a mere $300,000 and pulling in more than $55 million. The influence of Psycho (''It's the granddaddy of all horror movies,'' says Carpenter) is everywhere from the tiniest details (Donald Pleasence's Dr. Sam Loomis is named after Janet Leigh's boyfriend in Psycho) to the casting of Jamie Lee Curtis as Halloween's shrieking heroine and babysitter in peril. ''It didn't hurt that Janet Leigh was her mom,'' says Carpenter, ''because everyone's a fan of Psycho.'' And Halloween.
PSYCHO (1960) Directed by Alfred Hitchcock
A charter member of the scary movie hall of fame (and don't even think of judging Psycho based on Gus Van Sant's remake). Many of its most renowned features are readily apparent: those startling cuts (more than 50 in the shower sequence alone), Anthony Perkins' neurotic mama's boy, Bernard Herrmann's shrieking-violins score. But Psycho's sneakiest tricks manifest themselves more subtlely. Take Hitchcock's decision to use a handful of different stabbers in Janet Leigh's slice-and-dice sequence: ''He kept changing it so the audience wouldn't be able to get a fix on Mother,'' Leigh, who spent seven days in that shower, told EW in 1999. ''At one point it was Tony's stand-in, at one point it was a woman. Never Tony.'' Bottom line: It still works.
SEVEN (1995) Directed by David Fincher
From the jittery, scratched celluloid of its opening credits onward, Seven oozes more apocalyptic doom and deranged creativity than any Brad Pitt movie has a right to. Before this film came out, gluttony, greed, sloth, envy, wrath, pride, and lust were just intangible words uttered in Sunday school. But by Seven's closing credits, the deadly sins have become the gruesome MO of a revelations-spouting serial killer so out of his gourd that he shaves off the tips of his fingers to avoid leaving prints. From its bleak, rainy setting to an unshakably grim finale, Seven is so nihilistic and disturbing it's hard to fathom how it ever got greenlit. We mean that as a compliment.