I don't have a best one, but I have been watching some of the entries this year and here are some I thought were interesting, either for being evocative (can't fit any worldbuilding in 200 words, you gotta make the player do it), sounded like fun, or struck me as clever. I think a lot of people who have never written an RPG before participate in this, so I don't know if any of them are playable, but I really enjoy reading them (and was curious if you'd ever done something like that). I want to try making one sometime.
no subject