Wow, what a great thread.
OK , I would like to focus the question as "If an expense is not in question...".
We have all been there, short on cash, in a hurry, ....yadda yadda yadda....The fast food meal that is quality (at least in the south) is a meat and three.
These Mom and Pop(often owned by a mom and pop) joints often offer a cheap and fast home-cooked meal that is great for any sales person. Just Pick a meat and three (veggies that is..lol) and your eating in 10 min, , out in 30 and you get to sit and read the paper or enjoy the silence for a half hour.
My favorite in Birmingham: "Niki's" off Finley Blvd, only slightly over "The Dawg House" in Centerpoint
My favorite in Nashville: : "The Pie Wagon" off Music Row