The only titles listed are those which have horror/science fiction/fantas stories. And unlike other areas of this site, they are grouped according to company rather than alphabetically. When I have a chance I'll put them into three sections.

Ace Magazines
Web Of Mystery

Strange Fantasy

Allen Hardy Associates
Weird Terror

American Comic Group
Adventures Into The Unknown
Out Of The Night
Unknown Worlds (later Best Synd. Features)

Artful/Comic Media/Harwell/Mystery

Weird Tales Of The Macabre (Mag)

Avon Periodicals
Eerie / Strange Worlds (18 on)

Better Standard Publications
Adventures Into Darkness

Beyond The Grave
Creepy Things
Ghost Manor / Ghostly Huants (20 on)
Ghost Manor (2nd Series)
Haunted / Baron Weirwulf's Haunted Library (21 on)
Many Ghosts Of Dr. Graves
Mysteries Of Unexplored Worlds
Outer Space
Out Of This World
Scary Tales
Strange Suspense Stories - Fawcett Publications/Charleton
Tales Of The Mysterious Traveler
The Thing! - Song Hits/Capita Stories/Charleton
This Magazine Is Haunted - Fawcett Publications/Charleton
This Magazine Is Haunted (2nd series)
Unusual Tales

Comic Magazine/Quality Comics Group
Web Of Evil

Crestwood Publishing
Black Magic

DC Comics
Black Magic
Dark Mansion of Forbidden Love (ForbiddenTales of Dark Mansion)
DC Science Fiction Graphic Novel
Elvira's House of Mystery
From Beyond The Unknown
House of Mystery
House of Secrets
Mystery In Space
Secrets Of Haunted House
Sinester House of Secret Love (then Secrets of Sinester House)
Space Adventures
Strange Adventures
Tales Of The Unexpected
Time Warp
Unexpected (Formerly Tales Of)
Weird Mystery Tales
Weird War Tales
Weird Worlds
Witching Hour

Dark Horse
Basil Wolverton's Gateway To Terror
Basil Wolverton's Planet Of Terror

Four Color
Ghost Stories
Outer Limits

EC Comics
Haunt of Fear
Shock Illustrated
Shock Suspenstories
Tales From The Crypt (formerly Crypt of Terror)
Vault Of Horror
Weird Fantasy
Weird Science
Weird Science-Fantasy (then Incredible Science Fiction)

Eerie Publications
Horror Tales
Tales From The Tomb
Tales Of Voodoo
Terror Tales (Mag)
Weird (Mag)

Fawcett Publications
Beware Terror Tales

First Publishing/Berley Publishing
Classic Illustrated

Elliot Publishing/Gilberton Publications
Classic Illustrated (Classic Comics 35 on)
Classic Illustrated Junior

Gillmore Publications
Weird Mysteries

Gold Key
Twilight Zone (Dell Publishing/Gold Key/Whitman)
Boris Karloff Tales Of Mystery (formerly Boris Karloff Thriller)
Ripley's Believe It Or Not True Ghost Stories

Harvey Publications
Chamber Of Chills
Tomb Of Terror
Witches Tales (Witches Tales/Harvy Publications)

Major Magazine
Web Of Horror

Adventures Into Mystery
Adventures Into Terror
Adventures Into Weird Worlds
Amazing Adult Fantasy
Chamber Of Chills
Chamber Of Darkness
Clive Barker's Hellraiser
Crypt of Shadows
Fear (Adventures Into) 1-9 horror reprints
Journey Into Mystery
Journey Into Mystery (2n'd series)
Journey Into Unknown Worlds (formerly Teen)
Marvel Tales
Mystery Tales
Mystical Tales
Strange Stories Of Suspense
Strange Tales
Strange Tales Of The Unusual
Strange Words
Tales Of Suspense
Tales To Astonish
Tower Of Shadows
Uncanny Tales
Uncanny Tales
Unknown Worlds Of Science Fiction (Mag)
Vault Of Evil
Weird Wonder Tales
Where Monsters Dwell
World Of Fantas
World Of Mystery
World Of Suspense

Now Comics
Twilight Zone

Master - Merit Publications
Dark Mysteries

Pacific/Eclipse Comics
Berni Wrightson, Master of the Macbre

Periodical House (Ace Mags)
Baffling Mysteries

Prize Publications
Strange World Of Your Dreams

Red Circle (Archie)
Chill Adventures in Sorcery
Red Circle Sorcery

S.P.M.Publ/Aragon Publ.
Weird Tales Of The Future

Seaboard Publ./Famous Authors Ill.
Stories By Famous Authors Illustrated

Skyward Publishing
Nightmare (Mag)

St. John Publishing Co.
Strange Terrors
Weird Horrors

Standard Comics/Visual Editions
Out Of The Shadows

Stanley Publications
Chilling Tales Of Horror (Mag)
Ghoul Tales (Mag)

Star Publications
Startling Terror Tales
Terrifying Tales

Star*Reach Productions

Story Comics
Mysterious Adventures

Superior-Dynamic Publications
Journey Into Fear
Strange Mysteries

Toby Press/Minoan Publ. Corp.
Tales Of Horror

Trojan Magazines/Merit Publishing

Warren Publishing
Creepy Magazine
Eerie Magazine

Youthful Magazines
Beware - Youthful Magazines
Chilling Tales (formerly Beware)

Ziff Davis