Asheville should be high on your list. From the unique beers and dishes to hiking and rafting, there is something for everyone is this quaint little town tucked away in the Blue Ridge Mountains.
The Grand Canyon is a must do Natural Wonder of the World. There are so many things to see and trails to hike. I strongly believe, no matter your skill level or the length of time you have available to hike, you should make Bright Angel Trail a must do hike. It will change you in ways you did not expect.