I've got around 900-1,000 horror flicks in my collection. But here's 100ish Horror Flicks I would recommend for starters...
The Abominable Dr Phibes
A Cat In The Brain - Lucio Fulci, this has one of the best openings to a movie ever!!
Alligator
An American Werewolf In London
Attack Of The Mushroom People
Bad Taste
Basket Case
The Birds
The Black Cat - Bela Lugosi and Boris Karloff without make up in the same movie!!!
The Blind Dead
The Blob (original or remake)
Blood From The Mummy's Tomb
Brain Damage
Brain Dead - Dead Alive
Brain From Plaent Arous
Bride Of Frankenstein
Burial Ground
Cellar Dwellar
Cemetary man
C.H.U.D
C.H.U.D 2, Bud The Chud
City Of The Living Dead
Coffin Joe's "This Night I Will Possess Your Corpse"
Coffin Joe's "At Midnight I'll Take Your Soul"
Creepshow
Creepshow 2
Creature From The Black Lagoon
Curse Of The Doll People
Dawn Of The Dead
Day Of The Dead
Demons
Dolls
The Exorcist
The Fly (either version)
Food Of The Gods
The Funhouse
Frankenstein (original)
Fright Night
Ghost Story
Ghoulies
The Giant Claw
God Monster Of The Indian Flats
Graveyard Shift
Halloween 3, Season Of The Witch
The Haunting (original)
Hellraiser 1 and 2
House Of Wax (with Vincent Price)
The Howling
In The Mouth Of Madness
Invasion Of The Body Snatchers (original or remake)
Invasion Of The Saucermen
Island Of Lost Souls (1933 version with Bela Lugosi)
Island Of Terror
It Came From Beneathe The Sea
It's Alive
The Legend Of Hell House
Luther The Geek
The Mask (original 1961 version in 3D)
The Monster That Challenged The World
Motel Hell
The Mummy (Boris Karloff)
Nightbreed
Night Of The Creeps
Night Of The Demons
Night Of The Living Dead (original and remake)
The Omega Man
The Omen
Phantasm 1-3
The Pit
Planet Of The Vampires
Pumpkinhead
Puppet Master 1-3
Q The Winged Serpent
Quatermass And The Pit - Hammer
The Reptile - Hammer
Return Of The Living Dead
Salem's Lot
Scanners
Scarecrows
The Stuff
Tenebrae (Dario Argento)
Terror Vision
Them!
The Tingler
Trilogy Of Terror
Twenty Million Miles To Earth
Twilight Zone The Movie
The Uninvited (1944 version, not the Korean flick)
Village Of The Damned
Zone Troopers
Also, go here and watch some of the movie clips, you'll find some really great films this way!
http://www.badmovies.org/movies/
here's a few examples...
http://www.badmovies.org/multimedia/moviesi/ymir1.mpghttp://www.badmovies.org/multimedia/.../braindmg1.mpg