I want to run a game of PDQ entirely based off Cards Against Humanity which is a game for horrible people. Cards Against Humanity that is. PDQ is for all sorts of people. I envision playing one round of Cards against Humanity. All the white cards you receive are the qualities of your character. Unless you're the GM and then the white cards you receive inspire the session. Completely off the cuff. No one knows what you're playing until after the round is finished. I think it would be a fun exercise in roleplaying for everyone involved. The GM especially would learn about GMing in an improvisational fashion.
Picture from google image search for "Cards Against Humanity"