CHARLOTTE, N.C. ( TheStreet) -- A new survey of consumer attitudes showed that airline customer satisfaction has improved for the second consecutive year and has reached its highest level in nearly two decades. Nevertheless, room for improvement remains. "Air travel remains an uncomfortable and costly experience for most passengers," according to the American Customer Satisfaction Index in Ann Arbor, Mich., which said that only subscription TV service and Internet service providers had lower customer satisfaction ratings. ACSI, which annually surveys customer satisfaction in 32 industries, said passengers give high marks to airlines for the check-in process, the ease of making reservations, the courtesy and helpfulness of flight crews and baggage handling. All four areas scored 80 or above on the ACSI scale; 100 is the highest score. On the negative side, "Crowded seating, rising ticket prices, extra fees and poor service all contribute to a rather dreary travel experience," ACSI said. Rated lowest was seat comfort, which got a 63, which ACSI called "awful." Among the carriers, JetBlue ( JBLU) leads the industry, with an 83, up 2% from a year earlier. Southwest ( LUV) is second with an 81, up 5%. An aggregate of smaller airlines including Alaska ( ALK), Frontier and Spirit ( SAVE) -- yes Spirit, which is hated by some travelers, evidently a minority -- tied for third with a 72, down 3%. Apparently, many Spirit passengers know exactly what they are getting when they buy a ticket, which is to say nothing except for a cramped seat. Among the major carriers, cursed with unpleasant realities such as operating in congested airports and trying to connect large numbers of passengers, Delta ( DAL) leads the pack. The survey said Delta's rating gained 5% to 68, the carrier's highest rating in more than a decade. American ( AAMRQ.PK) had a 65, up 2%, while US Airways ( LCC) had a 64, down 2%. United ( UAL) remained at the bottom, with a 62 for the second straight year. United has had difficulty recovering from a botched merger with Continental, and it takes time for perceptions to catch up with reality as an airline improves its performance.