LAX: If you're airside in T6, try Jody Maroni's Sausage Kingdom - great bangers, top fries, and you can eat at the adjacent bar while sampling a microbrew. Or six.
PHL: Franchises seemed mediocre so I tried the Airport Marriott - leave the terminal, follow the signs. Superb nosh and there's even a smoking area. Downside: If you go large, it'll cost as much as your ticket.
ORD: Airside options similarly uninspiring. Far better nosh at the Airport Hilton, if you fancy a quick leg-stretch. Give it a miss if you're clastrophobic though - they forgot to build any windows...
AMS: Another option's Cafe Amsterdam, above the area near F/G-piers. Their recreation of a 'brown cafe' isn't too bad, the sate's cracking. And you can gaze on the pates of the masses queueing at security below.
LGB: I've not eaten in the terminal restaurant but if the grub's as good as the art deco trim, it'd be a winner.
LHR: T4 Conc Lounge wasn't bad...
Similarly defunct (I assume) is the best best for a 05:00 grease-fest on a cold winter's morning: Olive's Cafe at Beccles Heliport...