Budget airlines ... listed

Been looking for the most comprehensive list of budget airlines in the States? Look no more, thanks to the good people over at MSNBC. They have compiled this list, featuring the major players in the budget market, and include a brief guide to their services and route maps.
Read the full MSNBC story here

AirTran Airways
Phone: (800) 247-8726
Route Map
Hub: Atlanta
Where to find them: The major booking sites, aggregator sites
Tip: Most flights route through the Atlanta hub; check for very affordable upgrades on the day of travel. Serves many alternate airports; check the route map for a comprehensive list.

Allegiant Air
Phone: (702) 505–8888
Route map
Hubs: Las Vegas, Orlando
Where to find them: AllegiantAir.com
Tip: Based in Las Vegas, Allegiant Air flies to many smaller airports such as Bellingham, WA and Hagerstown, MD.

Frontier Airlines
Phone: (800) 432-1359
Route map
Hub: Denver
Where to find them: The major booking sites, aggregator sites
Tip: Almost everything routes through Denver; check the weather. Frontier offers a number of flights to Mexico's most popular vacation destinations.

Gulfstream International Air
Phone: (800) 523-3273
Route map
Hubs: Fort Lauderdale, Miami, Tampa
Where to find them: Not bookable on its Web site; available on the major booking and aggregator sites through codeshares with Continental.com.

JetBlue Airways
Phone: (800) 538-2583
Route map
Hubs: New York (JFK), Los Angeles/Long Beach
Where to find them: JetBlue fares are now available on major booking sites and aggregator sites.
Tip: Rows 12 and back have more legroom on many planes in the fleet.

Southwest Airlines
Phone: (800) 435-9792
Route map
Hub: None
Where to find them: Southwest.com
Tip: Seats are not assigned, so check in as early as possible on the Southwest Web site before leaving for the airport to ensure that you get a priority A boarding pass.

Spirit Airlines
Phone: (800) 772-7117
Route map
Hubs: Fort Lauderdale/Hollywood, Detroit
Where to find them: The major booking sites, aggregator sites
Tip: Spirit flies from some unexpected airports — like Atlantic City, Providence and Fort Lauderdale/Hollywood International.

Sun Country Airlines
Phone: (800) 359-6786)
Route map
Hub: Minneapolis/St. Paul
Where to find them: The major booking sites, aggregator sites
Tip: Sun Country offers service to additional Mexico and Caribbean destinations in the winter and early spring.

USA3000
Phone: (877) 872-3000
Route map
Hub: None
Where to find them: The major booking sites, aggregator sites
Tip: USA3000 serves warm-weather destinations in Florida, Mexico and the Caribbean.

Virgin America
Phone: (877) 359-8474
Route map
Where to find them: On its Web site, aggregator sites
Tip: All planes have special "mood lighting" as well as interactive seat-back TV's; touch the screen to choose a movie, listen to music or even chat with other passengers onboard.