Most airports have boring food; at best, a range of fast food choices or minimal cheesygreasy food to go with beer. International airports generally fare better - London or Amsterdam in particular, and also see my raves about Milan - but some domestic ones are catching on too.
Jetblue is a pioneer of a kind here. Along with their much advertised mantra of not serving food (though the food they do serve - Terra chips and real almonds - is miles better than the hated airplane staple of mini pretzels) Jetblue terminals tend to have a nice (though pricey) range of salads and take-away sandwiches. At JFK, however, they go further - a full food court provides options like sushi too - which even at its average is quite a change from fastfood hamburgers. Los Angeles airport used to have nice choices, like outlets of Wolfgang Puck's ever expanding chain, but I haven't been there for a while.
Interesting airport food popped up, of all places, at Denver airport. The last time I was here, at terminal A, sleek well-dressed women were inviting me into a small corner space complete with table service and dimlighting. I was, however, full from a silly Holiday Inn breakfast. This time, I noticed huge fastfood-looking signs called Chef Jimmy's that eventually led me to the same space - now brightly sunlit and not fighting a breakfast bloat. The menu is fastfood-inspired too, not unusual because the Jimmy in Chef Jimmy's is Jimmy Lambatos - who happens to also have co-founded Quizno's.
The short version - the food was surprisingly good. Salads that promised real vegetables and strange words like udon and mahi mahi floated about. Creamy tomato bisque, fresh tasty mixed greens instead of the ubiquitious iceberg and a final surprise - flaky, moist tasty mahi mahi. Service was hardly up to high dining standards but that did not seem to out of place with all the luggage lying around. Dont visit Denver for it, but definitely visit it while waiting for airplane food in Denver airport.