Off the top of my head, these are a few suggestions for better than totally revolting. Some are "healthier" than common airport food or just better.
O'Hare: Tortas Fronteras. The only restaurant of Bayless that I really like.
Vegas: Burke in a Box, has some stuff that is better than average.
Newark: There's a whole food court with better than average options, a Mediterranean place and another right next to it with all sorts of kebabs and stuff. Really the best selection...