I adore the island and countryside areas! A large number of my Sims have lived there. The city part doesn't get used much though. None of my Sims live in the city area, they just visit the venues. A very, very close second would be Sulani followed by Brindleton Bay, even though sadly my Sims don't live there much anymore due to the sick strays. I love the world though, it's one of my favorites, so I had to include it. Selvadorada gets a huge nod too, wish my Sims could live there, and also Strangerville. I love the red rock mountains in that world, so similar to Sedona here in the U.S.