I am going to wait until I get Island Living before I do anything as I would need the CAS and Build/Buy mode to really make fitting changes (like making new lots or homes with stilts in the water. It would be like this old home and wedding venue I once had in Sims 3, give Sims more tropical outfits, etc...).
Right now I am playing with one family but I usually start over with each new expansion as they give new choices that are for fitting for the sims I have in mind. Seasons allow my sims to pick a Season to get married in and now I can finally have a beach wedding on top of that. Next, I need that Magic game pack once it comes out as some sims should have special abilities due to the character they were based on. Once the game is completed or sims have everything that I personally need for them, I would probably start a more serious legacy play.
