Memphis:
Ribs - Corky's, Poplar Ave and ONLY Poplar Ave
Steak - Buckley's, not too far away from Corky's, prices will still allow you to hobby
Beer and a good burger - Flying Saucer, waitresses sport plaid skool girl outfits that beat Hooters all to death
More beer and great food - Bosco's Squared
Thai - Emerald, Wolfchasish
Sushi - Sekisui, due to FedEx Center we have pretty good fresh fish compared to other landlocked cities
Arnolds Country Kitchen in Nashville is where I have to eat EVERY time I'm in Nashville. Lunch is the best meat and veggies in town. In CA we just don't get it and as a proud southern boy, Its missed.
For BBQ, I drive up to Gutherie KY, just a short hop from Clarksville. I think they have some of the best I've found when traveling.
If you have a craving for gumbo while in Nashville, you have to stop at Razz's in Smyrna. It is the best gumbo and jambalaya in Nashville. Also great seafood, prime rib, and if you are there during the evening, near the weekend, someone might be playing some Jazz for you as you dine. It is reasonably priced, and one of my favorites in Nashville.