Followers: 1.1 million
Sample tweet: "@chrisnyder Sounds like you had an interesting flight! Was this your Flight Attendant? His name is Max: http://cot.ag/gyLSMC"
Southwest joins JetBlue as one of the few airlines getting it right on Twitter. Currently piloting the feed is @christimcneill, who does an admirable job helping road warriors do everything from rebook a flight to locate their frequent-flyer rewards. It's a thankless task, but one she handles with aplomb.