Ryanair has won the dubious honour of the UK's least-liked short-haul airline for the sixth year running.
The results from a Which survey of airline passengers ranked Ryanair at the bottom of 19 carriers flying from the UK.
A Ryanair spokesperson said the airline's success was not reflected in the survey.
The best performers were Guernsey-based Aurigny Air Service, Swiss Airlines, Jet2, Norwegian and Dutch carrier KLM.
The UK's other large airlines, Easyjet and British Airways came in at 11th and 15th, respectively, in the survey.
Easyjet beat British Airways's scores for food and drink, customer service and value for money, but both received low ratings for seat comfort.
Ryanair faced strike action in 2018, cancelled flights but refused to offer passengers compensation and introduced new baggage rules three times.
The airline, which predicts it will carry 141m passengers this year, also left passengers unimpressed with its boarding processes, seat comfort, food and drink offering, and cabin environment.
Which said "thousands of respondents" said they would never fly the airline again.
Of those surveyed who chose an airline that they would never fly in the future, 70% chose Ryanair.
However, independent aviation consultant Chris Tarry said, despite the low satisfaction ratings, customers were still happy enough to fly with the Irish budget carrier.
"Ryanair still represents great value for a huge amount of people. What they receive is what they expect."
Mr Tarry said the airline had endured "a tough year" but still generates "huge amounts of cash".
"Painful lessons have been learnt," Mr Tarry said.
A Ryanair spokesperson said: "Ryanair passenger numbers have grown by 80% in the past six years and Ryanair.com has become the world's most visited airline website.
"These facts reflect what customers want much more than an unrepresentative survey of just 8,000 people."