From years of reading these forums I've noticed that a request for the best attractions in a particular state will sometimes result in many good suggestions and other times very little. Rarely are there any suggestions for obscure out-of-the-way places but I've found many of these by reading blogs, mostly by fulltimers because they have the time to explore the areas that they are traveling through much more thoroughly than people who are merely on vacation.
Check some of these blogs -
http://www.hitchitch.com/links.html When you find a traveler who enjoys the same type of attractions as you do see if they have links to other blogs. You'll probably enjoy "Travels with the Blonde Coyote", a blog by a boondocking writer who's also a wonderful photographer.