the plot: Following the death of a fellow priest, Father Loomis (Pleasance) finds a key to a hidden underground vault in an abandoned Los Angeles church. Inside the vault is a mysterious canister filled with a bizarre green liquid. Loomis soon learns the dead priest was the last member of The Brotherhood of Sleep, a shadowy sect dedicated to keeping watch over the canister. In order to determine what the vessel holds, Loomis enlists the aid of Professor Howard Birack (Wong) and his team of graduate physics students, including Brian (Parker) and Catherine (Blount). The students soon discover the canister contains the essence of Satan himself, eager to return to earthly realms to pave the way for his father, the all-powerful Anti-God. Old Scratch exerts his eldritch influence on the church, turning students into zombies and leaving the survivors engaged in a desperate battle for survival.

why it's good: Prince of Darkness has a sheer, inexplicable creep factor that makes it a textbook example of how great B-movies can be. Maybe it's the music-Carpenter provides the score for "Prince of Darkness," a thudding, synth-heavy composition that makes a poorly lit tank of green goo absolutely terrifying. Maybe it's the leisurely pace at which Carpenter sends each hapless grad student to an untimely demise, or the squirm-inducing shots of zombified homeless people descending on the church (keep an eye out for Alice Cooper's cameo), or the particularly gross bit where a horde of beetles reanimate a corpse to deliver the message, "Pray for death." The film isn't particularly gruesome, but what it lacks in blood and guts it more than makes up for in suspense. Don't pay too much attention to the muddled mess of theoretical physics Carpenter stuffs into the movie, though-it distracts from an otherwise intense, shudder-inducing flick.

why you should own it: Sadly, Universal's DVD of Prince of Darkness contains nothing but the film. While it's not totally worth buying unless you can pick it up for cheap (Amazon.com lists it at $14.99), it's a must rent.