Steampunk done well is always very good, but perhaps it's too art-reliant. Fantasy's kinda overly cliched, and done wrong can end up a monster-of-the-day affair with a static green mountains background. Scifi requires deeper insight and much more planning than most other fields, as well as some believable technobabble. Horror is something only a select few can accomplish. Supernatural allows a good deal of liberty, and easy transitions between art styles. Dystopian or Apocalyptic requires both passable scenery and strong characters to set the atmosphere. I'd say Supernatural might be your best bet, especially given your familiarity with Parallel Dementia, which was a stellar example. You'll have to establish continuity, and be careful not to machine-gun in new characters, and if you choose to add actual magic make sure to make a single decision between Functional and Handwave. It would be interesting to see what you could do with the world of The Hunted, as I'm still working out kinks in my spare time and trying to get everything to fit together nice and snug, a stand-alone story might help me see the gaps, and it's probably helpful to have someone with a world in their mind to make suggestions from.