Post theme ideas for others to use here, or ideas you want to see someone make! Heck, you could post a new idea every time you take one from here!
I'll start with 5 ideas.
Hygiene Mafia (a reminder to your average internet poster to take a shower- on the daily)
Super Mario Mafia (based on enemies/characters from the Super Mario series)
Transformers Mafia (using G1 will be easiest)
The GOATs Mafia (game using once-in-a-generation elite-level athletes from a variety of sports leagues)
Italian Foods Mafia (bonus points if you make the Americanized foods scum)
I also have a bonus idea which I may or may not have taken from Discord.
Mafiaverse of Madness (based off the latest Marvel Movie, maybe even all of Stage 4 of the MCU)