Yahoo Travel shows Delta to be the most complained about airline.

“Delta dropped the ball this past year. One DOT official attributes the airline’s most-complained-about status to its merger with Northwest. Regardless, Delta has some work to do: it was the worst offender in nearly all categories, especially flight problems, reservations, and baggage. The airline’s response? Complaints are handled, said a spokesperson, “on a case-by-case basis in the order they are received.””

See original article at: http://travel.yahoo.com/p-interests-34489767