Going to collect some ideas in one place.  Feel free to throw in your own 🙂

Active or Pending

Unnamed Island
 Robbie's current Wed

Space.. TOO!!
 open-world campaign available for one-shots at player request.  Quests varied to include a variety of RPG styles to suit the requesting group.

Sleep Project
  available horror/comedy one-shot

Undeveloped

We Shrunk The PCs
 this one has come up several times recently in different context.  Undeveloped, the basic idea is fighting through the challenges of being an inch tall in your own backyard.  I envision this unfolding as a humorous dungeon crawl, and likely only lasting a short time period

Dodgeball - Active
 this one would play out like a Beyond the Supernatural or White Wolf Hunter campaign.  The PCs would be members of a professional dodgeball team, unexpectedly pulled into the hidden world of the monstrous.  Winning the ADAA is clutch, but so is checking out the supernatural and maintaining the mask.  Dodge (+Av cap Perc), Duck (stance +Av -speed), Dip (ready action to Catch), Dive (standard action stacking +Av/San), AndDodge! (stacking +Av half-ranks).

Dark Sun - Active
 i've just always loved the Dark Sun world and wanted to use it in a campaign (although likely in a heavily reimagined format focusing on the flavor, not the specifics).  This would be the closest to a traditional fantasy campaign of ones in my current docket.  total new map, limited races of which folks must be one, would present a very good chance for group world building.  magic might work weird, not wild, but more caveats than normal.  additional dimensional aspects.  

"Mob" Suggestion
 a couple players insisted that this had come up a couple times, and so therefore added to the list  

Future RandWorld - Active
 one of the ideas i've been playing with most recently, leaning into events a couple hundred years after the utopia at the end of the WoT books.  not heavy on fanfic, just ease of having prebuilt real history for non-readers.  would stand out the most for being a Rennaissance time period rather than stone/middle ages.  definite limits on the magic system but pretty straightforward ones, elemental caps and specializations, lots of counterspelling and disabling other casters.