Here in my great State there are many place of interest.
I guess it would depend on what you want to see.
There is Virgin Falls in Wilderness Pocket, now owned by Bridgestone Firestone. To accces this you need to hike but what a beautiful place. There are several waterfalls along the trail plus the Caney Fork River in the gorge.
Then there is Fall Creek Falls. The tallest waterfall East of the Mississippi. You can drive right up and walk only a couple of yards to see it. It is also a great camping area full of trails and other sites as well.
If you are a Civil War enthusiast in my home county is the gateway to the south. The battle field that changed the course of the war. Fort Donelson National Battle Field. It is located in Dover Tn and very small town right on the shores of the Cumberland River.
Or there is Shiloh National Battle Field. The Battle that changed the war would be fought. This is rather large park with much to see and learn.
If you are into pearls check out Birdsong Bay on Kentucky Lake, yes it is still in Tennessee.
Chattanooga offers Rock City, Battle in the Clouds and an aquarium who's primary focus in on the Tennessee River. how it is formed and the wildlife the inhabits it.
Everyone knows of Pigeon Forge and Dolly Wood along with the Great Smoky Mountains
For an added treat search Google images of these places. A picture of worth a thousand words.