Which of these rp ideas should I make an rp out of?

•social media- okay so every character is based off of some sort of social media in some way or another and it reflects on their personalities and they go on a road trip all together and go on vacation
•1920's mobsters- you've got flappers and jazz and art but then there's also the monsters and things go kinda crazy
•Victorian era- there's arranges marriages and scandals and deceptions and fighting and drama and all the shabang
•a werewolves and vampires selection- I think it might be more like a world selection, but the vampires and werewolves kinds are both dying off and their only chance for survival is to breed with each other.
•planets- or a world selection where everyone is based off of a planet or something like that.