Action/adventure! and fantasy and sci-fi stuff are my bread and butter. Aliens, spacey settings, goblins and orcs, etc. I love narratives with a violent promise. Dark themes, too.
I like episodic RPs. By that I mean, ones that aren't expected to go on for months on the same story. Not exactly a one-shot, and not by any means a "long-term" endeavor. Same characters but written in short stories that can be summed up like an episode. I'm not very good at traditional "romance" themes. I'm also not good at writing as a whole cast of characters (but background NPCs are good to fill in the world and make it less empty). So a focus on a just our couple of characters is best for me.
I absolutely LOVE to develop characters and do scene setting.
...and obviously, as this is an adult-writing site, I love writing about sex. I write it in a range from loveless-primal-fucking to sweet-and-intimate-lovemaking. Though I probably have more experience writing it in the former than the latter.