Yeah, Potbelly is good, but there are a number of other good places in the new MDW terminal. The Buffalo Wings at Millers Pub near B15 are exceptional, and I can get them done with only a little breading so I don't break the bank on the Adkins diet.
AUS is my personal nirvana, since when NJ was flying there they had three BBQ places. The red beans and rice and sausage are great in MSY. In DEN the Meson Ole in B terminal makes a mean burrito, you just have to ask for the 'mas caliente - not for gringos' hot sauce from the prep area to get the authentic experience. In PIT, the secret place is the Wok and Roll in D terminal, since they make the food to order (though the quality has slipped a slight amount since the D terminal is so frickin' dead these days). In IND the best place to get chow is the FOX Cafe in terminal C across from gate C-4. They have great salads, burgers, and hot wings. My personal fave at ORD is the Burghof near gate C-24. Their corned beef sandwiches are to die for.
I obviously take airport food very seriously.