Not sure if your plans are with kids or not, and if so don't know what the age(s) are. Some places to consider....
Huntsville, AL - surprisingly has much more than just the space center (which is really cool in and of itself). Very affordable.
Savannah, GA - Great without kids or older kids. Lots of good eats and history.
Tybee Island, GA - next to Savannah and great with little kids. "Very beachy" and low key. Great for having no schedules.
Asheville, NC - my family lives in the area so we visit often. Very "artsy" community. Lots of outdoors stuff to do - hiking, parks, picnicing. Continually has different festivals every weekend.
Chattanooga, TN - more than just the aquarium. Affordable.
Gatlinburg, TN - the mecca of all things over the top and border-line tacky. However, my kids loved it. Water slides, putt putt, racing cars, oddity museums, etc.
Have fun!