Everyone loves a good flight deal. Nonetheless, that cheap airfare can sometimes come with a catch. WalletHub recently compared the nine largest U.S. airlines along with three regional carriers across more than a dozen key metrics to determine which carriers are the best in 2019. In addition to cost, WalletHub analyzed safety, in-flight comfort, animal-related incidents as well as baggage, departures and complaints to give air travelers a better idea of where each stands. Here are the results.

Alaska Airlines is the best overall airline in 2019, according to WalletHub's research. The Seattle-based carrier was the only one to earn a total score above 60 in large part due to being recognized as the safest airline last year. It fares well across most categories, including fifth for cost.

Delta Air Lines ranks best among the Big Four thanks to boasting the lowest rate of cancelations, delays, mishandled luggage and denied boardings. Last month, Delta earned top honors for airline quality.

Serving Alaska, American, Delta and United Airlines, Skywest ranks best among the regional carriers WalletHub analyzed. Only Alaska and Spirit Airlines fared better in terms of safety last year while only ExpressJet and Southwest received fewer consumer complaints.

A favorite among budget-conscious flyers, Spirit Airlines trails only Frontier Airlines in terms of cost but only Frontier is worse for consumer complaints.

Based in College Park, Georgia, ExpressJet is the most pet-friendly airline that WalletHub analyzed, tying Envoy Air with no incidents. The carrier also tied Southwest for the industry's lowest consumer-complaint rate in 2018.

While cost is the one factor holding Hawaiian Airlines back, customers will be pleased to know that only Delta fares better for reliability. The airline also excels at safety and pet-friendliness.

United Airlines doesn't stand out in any one category but did finish second for comfort and third for reliability. Recently, the airline's CEO, Oscar Munoz said the aviation industry is in need of some changes.

JetBlue is the most comfortable airline, WalletHub found. The popular airline offers a superior in-flight experience that includes free amenities like Wi-Fi, extra legroom and complimentary snacks and beverages.

Southwest Airlines has garnered a plethora of unwelcome headlines in wake of the Boeing 737 Max grounding but remains one of the best airlines as only ExpressJet saw fewer customer complaints in 2018.

American Airlines fares worst among the Big Four carriers, ranking ninth among the 12 airlines WalletHub compared in terms of reliability and just sixth for comfort.

American Airlines Group subsidiary Envoy Air ties ExpressJet in terms of pet-friendliness and ranks middle of the pack for consumer complaints and safety.

If affordability is your top priority, Frontier Airlines can't be beaten. Unfortunately, those cheap tickets are where the pros end as Frontier ranks last for comfort and tops in terms of consumer complaints.