Long Hunter and the pull over areas on Natchez Trace Pkwy are my favorite hiking spots in middle TN. Henry Horton is good if you want a quick backpaking campsite or easy 5+ mile hike.
I actually haven't been out hiking and camping this summer seeing as how I broke some bones in my foot but I have knocked out most of our state parks.
To me west TN spots are kinda hit or miss while east TN is nothing but Tolkien tier.
Got an email or something I can shoot you more info at?