I'd be interested in the supernatural, time travel, superhero, and generations pack. I'm not a "mundane" player. I don't want a game where the most fantastical element is that I can go outside and see other people.
But all the fantastic stuff I want still needs a baseline of normalcy. And as much as I'd like werewolves and faeries, or superheroes, or medieval and time travel, I think the game desperately needs gameplay developed for sims that aren't adults. Babies are useless. Toddlers have nothing to do but relentlessly train skills. Kids have nothing to do and only four aspirations, so there's no reason to play different kids differently. Only with teens can you start getting rewarded for doing anything differently, and they're basically just young adults who go to school instead of work, adults are just young adults with some extra lines on their faces, and elders are just adults with more wrinkles who will get a negative moodlet if they exercise too much.
So ... generations. Give me as much reason to play a toddler, or child, or elder as a young adult. Make playing a teen substantively different from playing a young adult. Add school dances, group projects for school, after school clubs, tutoring, big brother/big sister organizations, whatever. As it is, my toddler gameplay is "I'll play this until I get tired, and then I'll just say I could have maxed out their skills, cheat them up, and have their birthdays." My child gameplay is, "I'll get them up to an A in school, but I'm not going to bother hitting all these very specific milestones for achievements, so I'll just max out their skills and age them up." My elder gameplay is practically non-existent.