Most of the world's international airports are located either in the middle of nowhere, or in suburban sprawl where the nearest place to eat is the local Applebees or Olive Garden. Saigon is a bit different, at least until the new airport is built (and who knows how long that will take). Down a short alley next to the gas station by the airport exit gate and just down from CT Plaza is Quan Chi Bang, which follows the theory that doing one thing well is the best strategy.
26 pieces of chicken and a couple of beers cost us about $6 each. Saigon is the only place I've been where you can eat delicious, local food while looking at the control tower of the city's airport. It's a little bit of a drive if you live near downtown, but it's completely worth it. And, if you're arriving in the city and you are too hungry to wait until you get into town, skip the Burger King at the international terminal and simply walk to Chi Bang. Order up a pile of chicken, and you're good to go.