Southwest Airlines Co. is a major U.S. airline and the world's largest low-cost carrier, headquartered in Dallas, Texas. The airline was established in 1967 and adopted its current name in 1971. The airline has nearly 46,000 employees as of December 2014 and operates more than 3,400 flights per day. As of June 5, 2011, it carries the most domestic passengers of any U.S. airline. As of November 2014, Southwest Airlines has scheduled service to 93 destinations in 41 states, Puerto Rico and abroad. Southwest Airlines has used only Boeing 737s, except for a few years in the 1970s and 1980s, when it leased a few Boeing 727s. As of August 2012, Southwest is the largest operator of the 737 ...more on Wikipedia
JetBlue Airways Corporation, stylized as jetBlue, is an American low-cost airline. The company is headquartered in the Long Island City neighborhood of the New York City borough of Queens, with its main base at John F. Kennedy International Airport. It also maintains a corporate office in Cottonwood Heights, Utah. The airline mainly serves destinations in the United States, along with flights to the Caribbean, The Bahamas, Bermuda, Barbados, Colombia, Costa Rica, the Dominican Republic, Jamaica, Mexico, Peru and Puerto Rico. As of October 2013, JetBlue serves 84 destinations in 24 states and 12 countries in the Caribbean, South America and Latin America. ...more on Wikipedia
3. Virgin America
Virgin America, Inc. is a United States-based airline that began service on August 8, 2007. The airline's stated aim is to provide low-fare, high-quality service for "long-haul point-to-point service between major metropolitan cities on the Eastern and West Coast seaboards." San Francisco International Airport is Virgin America's main hub, but the airline also has focus city hubs at Los Angeles International Airport and Dallas Love Field. Virgin America's frequent flyer program Elevate provides award flights and other benefits to frequent fliers. Virgin America, though the brainchild of British entrepreneur Sir Richard Branson, is a U.S. airline. By law, no more than 25% of a U.S. airline ...more on Wikipedia
4. Frontier Airlines
Frontier Airlines is a United States ultra low-cost airline headquartered in Denver, Colorado, USA. The carrier, which is a subsidiary and operating brand of Indigo Partners, LLC, operates flights to 60 destinations throughout the United States and near international destinations. The airline maintains a hub at Denver International Airport with focus cities at Cleveland-Hopkins International Airport in Cleveland, Ohio, at Trenton-Mercer Airport near Trenton, New Jersey, at Washington Dulles International Airport near Washington, D.C., and at O'Hare International Airport in Chicago, Illinois. Also, through a code-share agreement with Great Lakes Airlines, the airline connects passengers to ...more on Wikipedia
5. Sun Country Airlines
Sun Country Airlines, is an American airline headquartered in the Minneapolis–Saint Paul suburb of Mendota Heights, Minnesota. Sun Country uses nearby Minneapolis–Saint Paul International Airport as its main hub and flies scheduled and charter flights from Terminal 2-Humphrey to destinations in the United States, Mexico, Caribbean and Costa Rica. The airline provides charter service for the United States Armed Forces. ...more on Wikipedia