My *least* favorite free bar snack is the mix put out at Admirals Club lounges ... all the picking I have to do (of the sample on my napkin, not the big bowl, of course) to get past all the tooth-breakingly dry pretzels.
Favorite bar snack: mustard-flavored Gardetto's. Especially nice with a gin and tonic, not that I'd necessarily recommend that before boarding a flight.
Think I'll run to the store and get some right now.
Favorite appetizers: potstickers, mozzarella cheese sticks ... oh, heck, I like all appetizers. Except, I'd like to say nachos, because I really love nachos when they're done well. But I've gotten really lousy nachos so many times in airport bars that I'm afraid to order them any more.