I have a family in each town, so there's one in an apartment, and will have more as kids grow up & move out. Most of them had been sitting in my library, created before I'd gone on an almost year long hiatus from the Sims. I chose the smallest household for San Myshuno, because of the limited space in the affordable apartments, forgetting that mother & daughter both have loves the outdoors traits & would have been better suited for one of the other towns. Makes for a good backstory though, dad dragged them to the big city so he could advance his tech career, and they're trying to make the best of it.
As for preference, I still like houses the best, in Oasis Springs being my personal favorite 'hood, especially for family-on-a-shoestring-budget play. You can find nice roomy homes at good prices there, and often the best collectibles, especially plants. I play lots of kids, so they need room to run & play, and a playground in the open space is always a plus. I also like the rocket ships, haven't quite figured out how to get one of those in an apartment yet. ;)