If you fly for work or pleasure, you know that your choice of airline can make a big difference in the overall experience. Many people are loyal to one company, swearing their favorite carrier is the most reliable, least expensive, etc.

In an ever-changing industry, with merging companies and new baggage fees and restrictions, it’s more challenging to know which one is the top performer.

In March 2019, MONEY Magazine published the results of an airline study. They compared hundreds of data points across the major domestic airlines — weighing 39 factors including the average cost, price changes, fees, customer experience, and on-time performance — to determine the country’s best—and worst.

Here’s where the airlines landed.

1. Alaska Airlines

• Avg. price per roundtrip flight: $407
• Avg. price per kilometer flown: $0.16
• Share of on-time arrivals: 82.70%

For the second year in a row, Alaska Airlines earned MONEY’s best domestic airline title.

Alaska boasts the highest customer service rating among U.S. airlines, according to Travel + Leisure, as well as some of the shortest delays. Value’s there too. The airline offers the second-lowest ticket fares among U.S. airlines, at about 16¢ per kilometer, according to Rome2Rio.

Formerly a small-market airline servicing mostly the West Coast, Alaska expanded into dozens of new markets after its merger with Virgin America in 2016. In 2018 the company announced a new nonstop route between New York City and San Jose and opened a new airport lounge in New York’s John F. Kennedy International Airport.

Alaska Airlines’ other major perk comes from its popular loyalty program, named the best for frequent fliers by industry expert FlyerTalk in 2018. Unlike most other rewards systems, Alaska fliers can redeem their miles for flights on a number of partner airlines, such as Emirates and American. The airline also sold miles for a little bit cheaper in 2017, according to The Points Guy founder Brian Kelly.

Finally, frequent fliers agree the airline offers top-notch customer service: Alaska has won J.D. Power’s customer service survey award 11 years in a row—and the airline shows no signs of slowing down in 2019.

2. Southwest

• Avg. price per roundtrip flight: $396
• Avg. price per kilometer flown: $0.27
• Share of on-time arrivals: 78.99%

3. Delta

• Avg. price per roundtrip flight: N/A*
• Avg. price per kilometer flown: N/A*
• Share of on-time arrivals: 85.62%

4. Spirit

• Avg. price per roundtrip flight: $254
• Avg. price per kilometer flown: $0.15
• Share of on-time arrivals: 80.63%

5. American

• Avg. price per roundtrip flight: $353
• Avg. price per kilometer flown: $0.24
• Share of on-time arrivals: 78.03%

6. United

• Avg. price per roundtrip flight: $417
• Avg. price per kilometer flown: $0.33
• Share of on-time arrivals: 79.77%

7. JetBlue

• Avg. price per roundtrip flight: $389
• Avg. price per kilometer flown: $0.32
• Share of on-time arrivals: 70.59%

8. Frontier

• Avg. price per roundtrip flight: $311
• Avg. price per kilometer flown: $0.16
• Share of on-time arrivals: 68.82%

Methodology for the study

MONEY analyzed 1,600 data points for about 80 air carriers, including the nine leading domestic airlines and about 70 of the largest international airlines. Price factors were weighed most heavily in determining the rankings.

Criteria included average cost per kilometer, average price of a coach flight, and year-over-year price changes; percentage of on-time arrivals and average length of delays; and customer satisfaction ratings for food, in-flight and customer service, value, comfort, loyalty programs, and in-flight entertainment.

Criteria for domestic airlines also included baggage fees and flight change fees; canceled flights, delayed flights, and delayed flights due to carrier; overall experience rating, mishandled bags, and consumer complaints; and year-over-year improvements on all of the above.

Hawaiian Airlines was excluded from domestic airlines because of a substantial lack of data.

Data providers for all three rankings include Rome2Rio, FlightStats, Skytrax, Travel + Leisure, American Customer Satisfaction Index, U.S. Department of Transportation, J.D. Power, and the airlines.

* The average roundtrip flight for Delta was $411.60 in 2017, according to Rome2Rio, but the data provider didn’t have the necessary data for 2018. Median airfares were used for Delta’s 2019 ranking calculation instead.

Source: MONEY Magazine