I just got back from a trip to Nashville. We had a great time by the way, even though I can't stand country music. My GF loves it, I went because of the Titans/Colts game and Jack Daniel's Distillery
BUT... We went to three brewpubs in Nashville: Big River Brewery, Blackstone Brewery,
and Bosco’s Nashville Brewing Company.
Bosco's was by far my favorite. They tap a cask every night around 5 btw if you like that sort of thing. I'm into casks so I liked that. Blackstone didn't really impress me, but I wouldn't say don't go. They had an Oktoberfest ALE which was a first for me. Interesting to taste the difference between a beer which is usually a lager.
Try to make it to Jack Daniel's if that's your thing. That was an awesome tour and well worth the 1.5 hour drive down there.