RPG-Chronicles is a fledgling RPG business which currently hosts many roleplays, both original and fan based. They are looking for artists, concept design members, and publishing experienced individuals to get their ideas from the drawing board to the press.
If you are looking for horror, try Twilight in New Orleans , an original premise set in New Orleans, or Ever Green. Both these sites will be under "Twilight and Shadow", their horror based RPGs.
The key to the above sites, is to put all the relevant information into a RPG setting guide, complete with rules, character creation guides, and possible storylines for would be Storytellers.
Star wars? Well I would try The Jedi Praxeum. A site based 87 years after Return of the Jedi.
If you have an interest in assisting RPGC, here is a thread where they are working on the origins of Werewolves and Vampires. Quite original. I hope they make it an RPG guide. Would rock as a game. Here is the link Origins
There are other sites, but too many to list, so I named those which usually are popular.