Young adults for me, and skewed towards males. My sims do have children, but raising those properly isn't important to me. The kids run wild and have fun (admittedly for some "fun" means excelling, but those are rare). I enjoy keeping my sims around for a long time, playing with aging off and re-using the characters in side saves. They are all connected by friendships, mentorships, debts, rivalries and shared experiences going back to as far as 2016 - lots of drama potential. Only relationship/infidelity drama doesn't interest me.
But I also play with a strict backstory and a changing political landscape in mind, that locks many options for some or even for all households. It can get annoying when I look up solutions for problems and all of the internet is "just use x", when using x isn't allowed (or doesn't exist) in my setting.