This year it was named the least-complained-about airline by consumers; last year the Bureau of Transportation Statistics declared it the third best airline, with an 83% on-time takeoff record. But now Southwest has something else to celebrate: its 39th anniversary! Okay, okay, so 39 is maybe, shall we say, an odd year to celebrate an anniversary, but we don't really care. Why? Because they're using this as an opportunity to offer a flash sale on flights, with rates starting as low as—you guessed it—$39!

Some flights we found available for $39:

Flights available for $79 (which is still a great rate!):

Flights are available for travel anytime between September 8 and November 17, 2010. Booking has already begun, and ends June 24, 2010, at 11:59pm Pacific Time. See the official Special Offers page for more details and to book your flight.

Joshua Pramis is an online associate editor at Travel + Leisure.