Dunno if I'd say I can't live without it, but of late I've become impressed with Cindy and Caleb's port of
Pleasantview into TS3. This might seem an odd choice, given that I never played TS2, but I like the layout of the town. It's easy to get around in thanks to being nice and compact with grid streets. And there's plenty of room for expansion. The handful of palm trees look a bit out of place, since otherwise the place looks like it could be a small town in northern Ontario, where palm trees are not normally encountered. But other than that the town gets very high marks from me.
I've actually taken the empty version of the world and populated it with a bunch of my CAS sims, supplemented by some of the families from the bin. This has been the primary world I've been playing of late.