The "Encounter" restaurant on top of the Theme Building at LAX is a good place to eat. I eat there nearly every time I'm flying a red-eye back to NY. It has received favorable reviews in several newspapers and magazines, also. Not cheap, certainly, but better than airplane food by a mile!
Washington National's new terminal has a couple of decent places, including a Legal Sea Foods and a California Pizza Kitchen. Unfortunately, I almost never get to use them, because the frequency of flights to NY is so great that I never have a long enough wait.
Bruce