I am based in Memphis and you really can't beat M01, Dewitt Spain for heading downtown. AWM, OLV, NQA - they all have their place for different reasons. Tune is a slam dunk in Nashville. I did fly into BNA last weekend and was pleasantly surprised with how that went. Controllers were fantastic and Signature treated me very well (fuel prices hurt) but I have also been to PCB and Destin in the last month and those prices have made 6.50/gal seem tolerable lol, Smyrna is fine, but a little ways out to Nashville proper.
I second the vote Tune for Nashville and Dewitt Spain for Memphis as stated above though.