A few years ago when I started to experiment with vegetation detection from imagery in scenProc I was looking for a test area with good imagery. I ended up picking the island of Nantucket, since it is a nicely sized island and for the US there is a lot of free source data to work with.
Later I found out that Bill Womack was also working on a scenery of the island, so my test autogen moved from just an experiment to something that would become part of an actual scenery. And combined with the great custom autogen textures Bill made the result is really fantastic.
Now Bill has released this scenery, so if you are looking for a nice VFR destination or just want to enjoy the scenery and the custom autogen check it out.