Here are some of the things I like to RP (I don't like romantic RPs very much though):
Jane the Killer or one of my original characters preferred. I'm not the greatest with other canons, but I don't mind opportunities to learn. I love creepypastas.
Jazz Fenton or I have more than a few OCs, majority of them ghost OCs. I like a really cool story, like AUs and continuations from the end of Season Two or Three.
Normally Dib, but also a few OCs as well. I like playing the characters as teenagers (like a few years later after the show maybe)? I'm just not the greatest with child characters at the moment, but am willing to learn.
Sonic the Hedgehog
I like Shadow and Sonic the most, but I have a few OCs I can use as well.
I just really like fantasy and magical realism kind of stories, so having an RP that way would be fantastic too. I like playing angels, demons, and creatures I can come up with.
I love horror. I love monsters especially. Even an RP with a hint of fantasy in horror can be real cool too.