Actually, I have watched "The Descent" quite a few timesin the last couple months. It really holds up well to repeat viewings.

Good question. Dead Alive is pretty re-watchable since it isn't too long and just full of laugh and gore.

Others: Dawn 78, Shaun of the Dead, Bad Taste...

I find "Suspiria" to get a lot of replay. It's one of those movies that isn't really driven by plot, but I get caught up in the visuals and music.

Dawn of the Dead (78), Halloween, Texas Chain Saw Massacre (76), are my obvious "high-rewatch" movies, but here's a list of one's not too many people might mention:

-Nightmare on Elm Street
-American Psycho
-Man Bites Dog
-Zombie
-God Told Me To...Kill
-Ted Bundy
-Nosferatu (22)
-Last House on the Left

Really?!? You're right, I certainly wouldn't mention that one. That movie makes me feel dirty all over. I feel like I need to shower inside after watching it.

Some of my most re-watchable ones -
Freddy vs. Jason
Dead Alive
Re-Animator
and a lot of X-Files episodes that are horror-ish.

Night Of The Living Dead is always good for a spin as well.

"Last House On the Left" just isn't as funny after the first time. I can only take so many stabbings accompanied with synthesizer sounds.

I'd say "Hellraiser", just because there are so many quotes you can slowly digest and use in everyday life.

A L I E N or The Thing would be my most re-watched horror films.

Land Of The Dead is my most watched, then Dead Alive.

Others I could watch anytime are:
The Thing
Return Of The Living Dead
The Frighteners
Hostel

Same here!

Most definitely my most re-watched horror dvds are Shaun of the dead, followed by both Dawn of the Dead 78 and the remake. Others that would follow are:

The Frighteners
American Psycho
Alien

Alot of the popular movies have already been mentioned but I will throw in a few more of my favorites that I rewatch alot.

Dog Soldiers
Cabin Fever
From Dusk til Dawn
Blade
Ginger Snaps

Hard to choose the most re-watchable, but here are a few I watch regularly:

The Thing
Poltergeist
The Fog
Jaws
Friday the 13th
Near Dark
Phantasm II
The Burning
Dawn of the Dead '78
The Hitcher
Halloween

Fulci's Zombie. Gotta be the theme music!

Please continue the conversation here...

Return of the Living Dead
Alien
The Thing (remake and original)
Re-Animator
Jaws

Evil Dead 2
Army of Darkness
Re-Animator
The Thing
Halloween
Shuan of the Dead

I'm not entirely sure why, but one that I can't help but watch every single time I catch it on TV is Event Horizon.

definately 'Shaun of the Dead'

The ones I've watched the most (at least 4 times on DVD, not counting all the times before) are:

Shaun of the Dead
Dawn of the Dead (the original one, although I've watched the remake 3 times)
Evil Dead
Evil Dead II
Army of Darkness
Candyman
Lord of Illusions
The Haunting
28 Days Later

I've watched Halloween and Alien a bunch of times, but I kind of tired them out pre-DVD so I've only watched the DVDs once.

Hmmmmmm, I think I've watched PSYCHOS IN LOVE more times than I ever should have.

I wish I had a more unique answer, but I gotta go with the standards here: Jaws, Psycho, The Exorcist, Night Of The Living Dead, Alien, The Texas Chainsaw Massacre, Carrie, Halloween, Friday The 13th, The Evil Dead, A Nightmare On Elm Street, The Thing, An American Werewolf In London, Poltergeist, The Return Of The Living Dead, The Fly...etc.,etc.,etc. I watch these films regularly with no diminishment whatsoever in my enjoyment of them.
And I could watch all their respective sequels ad nauseum as well, despite (or maybe BECAUSE of) how bad some of them are.
Well, except for An American Werewolf In Paris, which commits the cardinal sin of being just plain BORING, even for a bad horror sequel.

"I've seen 'The Exorcist" about 166 times, and it keeps gettin' funnier, EVERY SINGLE TIME I SEE IT...!"

That film is my favorite new horror film of this year! I was completely terrified by that movie, and am now a gigantic fan of Neil Marshall. It was even better than "Dog Soldiers", which I also thoroughly enjoyed. I just hope that when it gets its domestic theatrical release, it isn't heavily cut, ala "High Tension". I heard a nasty rumor about a butchered, truncated ending. We'll see...