-Evil Dead (yeah, I know I'll catch some eye-rolling on this... but it really was scary. The second one *transitioned* into funny... and everything after that didn't even try to be scary)
-Night of the Living Dead (the remake was good, too. The zombies are coming. You're surrounded. They know you're in there...)
-Dawn of the Dead (I realize this sucker is full of sarcasm... zombies infesting a shopping mall... but it was still scary)
-Return of the Living Dead (who knew a dead punk chick could be so hot? Well, she leaves a mark on you when you're 11, and you see boobies)
-Exorcist (hard to beat the sheer horror of this one, especially for back then)
-Wizard of Gore (the goriest movie I've ever seen. Zero budget, which means *real* animal parts were used instead of fake meat and guts, which means the gore actually looks *better*. Aptly named)
-Friday the 13th (the first several, anyway. I'm even including the 3-d one. The series went in the shitter when they decided Jason should *really* be an alien-esque critter that crawls down people's throats... then came "Jason X" 'nuff said)
-A Nightmare on Elm Street (original. What a creepy concept. The best horror is that which is unavoidable... like knowing you can avoid Freddy, if only you don't fall asleep. The scene where Freddy is fucking the girl's mom, who is by that point a burning corpse, is still creepy. "One, two, Freddy's comin' for you... three, four, better lock your door... five, six, grab your crucifix... seven, eight, better stay up late... nine, ten, never sleep again!")
-Texas Chainsaw Massacre (the damn camera angles and super close-ups of terrified eyes darting back and forth is enough to make you go off the deep end)
-Motel Hell (Mmn, mmn! Farmer Vincent makes the best sausage around!)
-An American Wearwolf in London (we all really dug the cool-ass transformation scene back then. Almost funny now, but trust me, it was scary!)
-Jaws (along with Friday the 13th, has THE most familiar "oh shit, brace yourself for the attack!" music around. Might be responsible for giving me a bit of a shark-at-the-beach phobia)
-Alien 2 (the little "locator" devices they used were pure genius. Whoever thought that bit up knew the previously mentioned key to great horror: anticipating the unavoidable)
I'm getting tired, so that's it for now. :-p