I would like to add:
Child’s Play
The Evil Dead
Night of the Demons
Okay, I’ll cop to not being a connoisseur of horror films, American or otherwise, but why is The Birds not essential?
The first two. Spencer Tracy is a travesty.
Does “The Ring” count? I thought the American remake blew the doors off the Japanese original.
Blair Witch was one of the few I saw in the theatre, but I’ll admit it works better on the square TV screen. I don’t know why so many people hate it.
Seconding:
Evil Dead
Texas Chainsaw Massacre (I’ll go with the remake as well, but mainly for R. Lee Ermy)
Carpenter’s The Thing
Child’s Play
I’ll add The Blob (original one with Steve McQueen). That one freaked me out as a kid.
Jaws
The Hitcher
The Children of the Corn
How about Black Christmas (the original)?
The original launched (or at any rate was in the first wave of) a whole distinctly American subgenre of serial-slasher horror movies.
I dunno why the Brits didn’t do it first – they had Sawney Bean and Jack the Ripper in their history – but they didn’t.
The Thing (the original) - excellent acting, realistic reactions, excellent music score, and a whole lot of suspense. I thought the whole concept was realistic in terms of “what would you do if suddenly visited by an alien bent on devouring you?” Mad scientist who wants the alien, and heroic men (and one woman) who save the day.
Frankenstein - the original with Boris Karloff; the night after seeing it in the theatre as a child, I couldn’t get to sleep because I thought the monster was under my bed. Grandma heard me whimpering, and told me to come down stairs, and I leaped out of the bed.
I’ve liked a few of the Saw movies, but after awhile they seemed like the same-old-same-old.
The Conquerer Worm with Vincent Price (witchcraft and torture!) Haunted me for weeks.
Some, such as Jaws, I don’t think of as horror movies. Jaws - the acting was wonderful, the shark done well (given the time), and loads of suspense, but horror? No. To me, a horror movie haunts you long after you saw it; even the few Saw movies didn’t haunt me – I was interested more in how the victims escaped or died.
Some of these, like Frankenstein and Alien, straddle the horror/science fiction line.
ABBOTT AND COSTELLO MEET FRANKENSTEIN
ALIEN (an old dark house movie set on a spaceship)
BRIDE OF FRANKENSTEIN
CAT PEOPLE (1942)
DRACULA (1931)
ERASERHEAD
THE EXORCIST
FRANKENSTEIN (1931)
FREAKS
HALLOWEEN (1978)
HOUSE OF USHER (1960)
INVASION OF THE BODY SNATCHERS
THE INVISIBLE MAN
JAWS
KING KONG (1933)
THE LOST WORLD (1925)
NIGHT OF THE LIVING DEAD (1968)
THE PHANTOM OF THE OPERA (1925)
PSYCHO (1960)
THE TELL-TALE HEART (1953)
THEM!
THE THING FROM ANOTHER WORLD
THE WOLF MAN (1941)
Misery
I actually stopped writing short stories for a long time after watching that movie.