The Gaylord at Opry is supposed to be very nice and there's a boat inside. Also, right next door is the Opry Mills mall--Aquarium & Rain forest restaurants. These are off of Briley Parkway (TN155).
Unsure where you are heading on to, but to let you know, we have a lot of construction I-24/I-65 interchange. This is an area that gets congested anyway, but right now, we are talking 11 ft lanes, curving and single lanes. It gets scary and we are relatively local. Briley Parkway is the detour route around this.
DH works out of Chattanooga so we have made the trip several times when he was at headquarters this summer. Trying to think of the billboards and most seem to be for the places already listed above or winery & distillery (not kid places IMO) or shopping. Of course, sometimes we don't notice what is out there.
Overall, if you end up all the way to nashville, I will say that the airport locations tend to be much cheaper than the downtown locations. And the travel time to a destination downtown from the airport is about 15 min (heavy traffic).