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.

• The Fountain of Immortality - evocative


• Altimeter Red - evocative


• Get me pictures of spider-man!!!! - sounds like fun


• Space Station Collision - clever prisoner's dilemma


• Trash Animals - not really an RPG, but evocative


• Wizard Heist - clever tic tac toe