RPoL
Yup, if it can be played by posting, you will likely find it here. Welcome to this mad portal to the multiverses we call RPoL.
Some things that will make your time here more pleasant:
Please read the FAQs and the Policies concerning Adult & Mature Content. Consult also the Help System, especially if you intend to run a game or five.
Get to know the place and see how the flow is. Lots of folks here will help you out if you get lost or need info.
To find games: Wanted - Players
To find GMs: Wanted - GMs
To read interesting concepts being floated for new games: Game Proposals, Input, and Advice
If you just wanna hang out and chat: Community Chat.
There are other places, too, but let's not make a laundry list, hmm?
RPoL has one of the better toolkits for GMs I've seen anywhere. There's Good Stuff in there.
Whether you like it free-form, rules light, or downright crunchy, whether it's old-school, d20, indie games, or home-brew you're likely to find it here.
Have Fun,
D