Thought I'd list my humble (or embarrassing?) horror-ish movie collection. In alphabetical order, but sequels are after 1st part for clarity's (??) sake.
   I'm a scrooge at buying movies (especially on DVD) but whenever I see there's a horror movie (well, relatively new one, I'm not into B&W) on TV I tape it, and keep it if it's... keepable. :) (I was going to say 'decent' but it's not really a good word to describe horror movies now is it...)
   The (DVD) is clear, but when I've put (VHS) after a title, it means it's a bought video, not taped.

Apt Pupil

Creepshow I

Creepshow II

Christine

Cujo

Diary of Ellen Rimbauer

Dolores Claiborne

Dreamcatcher

Green Mile

Hearts in Atlantis

It

Kingdom Hospital (TV series)

Misery

Needful Things

The Rage: Carrie 2

Riding the Bullet

Rose Red

The Running Man

'Salem's Lot (1979)

'Salem's Lot (Remake)

Secret Window

Shawshank Redemption

The Shining

The Shining mini-series

Silver Bullet

Sleepwalkers

Stand By Me

Storm of the Century

Thinner

Tommyknockers

*gasp*
A bit of an unbalance here...

The Blair Witch Project

The Blair Witch Project II

Body Bags

Bram Stoker's Dracula

Constantine

Epidemic
(Lars von Trier movie)

The Exorcist, director's cut

The Exorcist II -- The Heretic

The Gift

Halloween

I Know What You Did Last Summer

I Still Know What You Did Last Summer

Memento
(ok ok, it's only a thriller, but at least it's a darn good movie -- how do you define what's horror and what's not anyway, by if it's scary/gory/horrible or not? Wouldn't work with me...)

Nightmare Before Christmas

Nightmare on Elm Street I

Nightmare on Elm Street II

Nightmare on Elm Street VII - New Nightmare

The Ninth Gate (DVD)

The Omen

Poltergeist

Psycho ('60)

Psycho II ('83)

Psycho III ('86)

Psycho '99

Ring

Rumpelstiltskin
(I wonder if I still have this... x) )

Saw

Saw II

Saw III

Scary Movie :)

Scary Movie II

Scream

Scream II

Se7en

Silence of the Lambs

Hannibal

Red Dragon

Sixth Sense

Thesis
(Spanish movie on snuff films)

Urban Legends

The Village

Well, at least you get some kind of a movie marathon out of these...