I’ve been to and slept in many airports (here is some advice if you have to sleep in one too). Ataturk Airport is the best I’ve seen thus far. Clean, very efficient security that gets you through quickly, and great shops with some variety and prices that don’t cause anal leakage. Plus free high speed Internet blankets the place.

Places that make you pay to get online can never be on a “good airport” list. You can check to see if the US domestic airports you might be visiting offer free wireless.