If there was only one place to visit in all of Florida, I'd have to say Siesta Key. It's more isolated than the others but isn't far from society either. It's located near Sarasota and is a short drive from Tampa. The water here is gorgeous. Blue green waters with white sand. You can rent out kayaks, go snorkeling, or hunt for seashells. This is the best place to go if you want to relax by the water. But if you're looking for more city life then I suggest Miami.