I'm in shock! Which airline gives you the best customer service? I'll give you a hint: The answer isn't any of the major "legacy" carriers. Mega-carriers US Airways , American (still owned by AMR), and United (now part of United Continental may be some of the biggest airlines in the country, but according to a recent survey conducted by Airfarewatchdog, they're far from the best, ranking eighth, ninth, and 10th on the consumer advocate's list of the Top 10 carriers. Even Delta Air Lines sports only a sixth-place rating on Airfarewatchdog's list. And Southwest's two brands -- Southwest proper and AirTran -- bracket Delta in fifth and seventh places, respectively. No, when it comes to providing top-level service for getting planes to arrive on time, running flights instead of canceling them, delivering baggage and passengers to their intended destination, and overall customer satisfaction, the No. 1 airline in the nation is Frontier Airlines, a subsidiary of Republic Airways . Here's how the rankings stack up, from top to bottom: Airline Rank Frontier 1st Place Virgin America 2nd Place JetBlue 3rd Place Alaska 4th Place Southwest 5th Place Delta 6th Place AirTran 7th place US Airways 8th Place American 9th Place United 10th Place How did Frontier Airlines earn "best in show"? Digging into the details on Airfarewatchdog's multiple surveys, which add up to the overall results shown above, the results do seem a bit curious. Frontier actually doesn't rank No. 1 in any of the subcategories examined. It's not No. 1 in uncanceled flights (that's Virgin America), or in on-time arrivals (Alaska Air holds that honor). Frontier's not the best in baggage handling, denied boardings, or customer satisfaction, either. Top marks in these categories go to Virgin, JetBlue, and JetBlue (again), respectively. Yet according to Airfarewatchdog, Frontier does a good enough job in each individual category to make it the best airline to fly, overall. Maybe that's why when it comes to picking "feeder" regional airlines to supply them, even the majors turn to Frontier's own parent company, Republic, to connect them with passengers aboard brands American Eagle, US Airways Express, and United Express. Apparently, good enough for them is also good enough for us.