American's offer competes with Northwest's latest deal. Destinations include Chicago, Denver, Honolulu, and Montreal.
American's new domestic sale is similar to AirTran's offer. Cities include Atlanta, Miami, and New Orleans.
Flights to Chicago, Miami, Amsterdam, and London are included in Northwest's offer. Travel is valid between January and early March.
Hawaiian's sale features departures from the western U.S. to Honolulu. Travel is valid between early January and mid-March.
Delta's Europe sale features London, Milan, and Pisa. Travel is available through mid-April.
