I have the Nightmare collection on dvd.
Jeepers Creepers 1 and 2
Friday the 13th (new blood and the final chapter)
Scream (all of them)
The Texas Chainsaw Massacre (2003)
Jason X
The Blair Witch Project (1 and 2)
Halloween H2O

And I'm planing to get Freddy VS Jason and Alien VS Preditor when they come out for sell.

I would add -

Demons 2 (glad you have 1)
Castle Freak
Return of the Living Dead 1 and 3 (and 2 when it comes out)
Nightmare on Elm Street collection (Freddy's Dead is cool in 3D and the encyclopedia is great)
Warlock 1 and 2
13 ghosts (remake)
House on Haunted Hill (remake)
Prince of Darkness
Candyman
Halloween (Limited Edition if you can get it)

If your into Aliens -
Alien Quadrilogy
Communion

If you're going for Leprechaun, get Leprechaun Pot of Gore Collection (5 DVD Set) on Amazon for only $45

If you're going to get Halloween, get Halloween: Limited Edition if you can get it used or the Divimax plue the tv version.

I'd be concerned about Session 9 getting boring after the first veiw - great rental to see in the dark though.

These are just my humble opinion

go to wal-mart and get every damn horror movie that you can find in the bargain bin.... they have a lot of great selections to choose from, well that is if you find it when it is just filled up..and if you like Italian horror (demons & demons 2) I`d add some Fulci to your collection...
Get TCM II and III

if you order online here are some links
cduniverse.com
Horror Movies.com
overstocked.com diabolikDVD
diabolik DVD is expensive but I usually browse through just to find obscure horror...

If you dont order online here are the best places to purchase horror... Circuit City, Wal-mart, target, & best buy... sometimes you can find some good deals at Suncoast

http://www.badmovies.org
anything *** or more there should be on the list if you're just going for horror movies. Although Evil Dead only got ** there for some reason...hmm...

here's my answer(in order of preference)

evil dead/evil dead 2/army of darkness:D

i just can't stand this movie. its so boring and stupid.

this is my preference

What angers me about some of these movies is that is will be hard to find the true, uncut versions. Like Dead-Alive, I've heard of a version that's 104 minutes long and one that is 97 minutes long. Sadly the 97 minute one is the only one I've seen anywhere, seven minutes is a lot of editing and nearly every scene is probably cut some.

ps~~~Added some new dvds to the list

does Braindead is 104 min long?

The ones i have got:
The legend of hell house
Firestarter
Alien
Aliens
Alien 3
Alien: Ressurection
Carrie
Resident evil
The night flier
Dead and buried
The others
The Blair witch project
Psycho(1998:mad: )
Bride of Chucky
Camp blood
Valentine
Friday the 13th part 2
Friday the 13th part 3
Friday the 13th part 6
Halloween part 1
Halloween part 4
Halloween part 5
Mimic?

At the post-office with my name on:
The omen
The silence of the lambs