If friendly staff and clean toilets are all-important to you, you might want to consider trying London Southend Airport. The 2017 Which? Airport Passenger Survey ranked it as the best London terminal for the fifth year in a row. It's not necessarily the first London airport most passengers would think of, but it's growing in popularity and is proud of its record of customer satisfaction.
It scored 84 percent overall, including top marks for staff friendliness and helpfulness. It was also rated particularly well for baggage reclaim, seating, toilets, queues at security and passport control.