JetBlue Airways, Frontier Airlines and Hawaiian Airlines rounded out the top five, the survey showed.
Singapore Airlines and Emirates Airline ranked highest internationally, followed by Thai Airways, All Nippon Airways and Air New Zealand, Zagat said.
Of U.S. airlines, Southwest Airlines had the best frequent-flier program and Web site.
Tampa, Denver and Minneapolis-St. Paul ranked as the top three domestic airports. The worst: New York's LaGuardia.
Domestic delays and cancellations topped respondents' list of irritants with 35 percent of the vote. Cramped seats and crowded planes ran a close second at 34 percent, while poor service rated 15 percent, followed by security delays (5 percent) and lack flight status information (5 percent).
Still, 44 percent of fliers said they traveled as much as they did two years ago.
Among the "outtakes" Zagat surveyors heard from frequent fliers: "I'd rather be a package on FedEx;" "Their planes make Larry King look young;" "If they could have pay toilets, they would;" and "Only good thing about first class these days is that you get to leave the plane first."