Call of Cthulhu
Adric's Insanity, Beyond The Mountains Of Madness Cardiff Campaign 2, Cthonian Lair, Delta Green - Operation: Struggle Within, Distortions from the Past, Ron Hopkins' Cthulhu Campaign, Unquiet Slumbers
Vampires
Alonia Slayers School, Darkness Falls, Darknight Sanctuary, Enter The Darkness, Vampire Tavern, Vampire's Opera, Vampires! A Dark Alleyway, Yahoo!: Immortal Blood
#Nightstalkers
Nightstalkers is a gothic horror roleplaying channel that uses the Fuzion game system to maintain fairness and consistency.
Andromorphia
[Messageboards] Freeform roleplaying. Players can be vampires, lycanthropes, daemons and other creatures relevant to a dark setting.
Dark World By Night
Realtime chat community for vampires, werewolves and other creatures of the night.
Downward Spiral
[WBS Chatroom] Dark fantasy themed roleplay, set in modern day New York. Players can be humans, vampires, werewolves and other fantasy races.
Hawthorne Manor
[WBS Chatroom] Modern day horror set in a sprawling haunted estate outside Salem. Players can choose from a variety of setting appropriate undead, mortals and extraplanar classes.
Nitemare
Nitemare is a play by post RPG, with horror, mystery, adventure, wars, intrigue, and magic, it has many creatures,and its set in a underworld medieval type atmosphere. Users can create their own creature and find a new city.
Regency Murder Mystery
[Messageboards] Freeform murder mystery game set in early 19th century London.
Shadow Dream
Players are caught in a dreamworld as a slave of the shadows and can choose to progress via a good or evil path. Includes application form, rules and progression chart. [AOL chatroom]
Surrender
Play-by-post game with a gothic fantasy theme. Players create a character and roleplay through the various ages and times.
The City of St. Sayat
Set in a city of darkness and wonder, controlled by the Vampyres and Werewolves that call it their home.
The Court of Roses
Horror/gothic RPG set in a mansion owned by vampires. IRC chat based.
The Midnight Cafe
A nightclub for those with a taste for the nightlife. Role-play as a vampire, werewolf, or character of your choice.
The Sword Foundation
Horror PBEM based on the Reeves-Stevens novels "The Chronicles of Galen Sword". Uses GURPS system for character creation.
Yahoo!: The Covenant of The Gods
Four Olympian Gods have formed The Covenant and created heros, known as slayers, to combat evil in the form of vampires, lycanthropes and sandmen. Player characters play keepers, who provide support to the slayers. Forum based.