For most people, an economy class seat is part and parcel of air travel – after all, it allows millions of passengers a year to fly all over the globe.

But as many experienced air travellers learn, not all economy classes are the same.

Some have smaller seats with a tighter width, others have minimal leg room, and others don't even have a TV screen installed inside the back of seats.

Skytrax, the UK-based consumer aviation agency, has released its annual "Best Airlines in the World" ranking for 2018.

The survey, which began in 1999, is an annual customer relations satisfaction survey that is among the industry's most professional and prestigious.

This year, it was taken by more than 20 million respondents – the results of which can be found below.

10. Japan Airlines

(Facebook/Japan Airlines (Facebook/Japan Airlines)

9. Lufthansa

(shutterstock.com/Belish (shutterstock.com/Belish)

8. EVA Air

(Facebook/EVA Air (Facebook/EVA Air)

7. Garuda Indonesia

(Flickr/Kentaro IEMOTO)

6. Cathay Pacific Airways

(Cathays Pacific (Cathays Pacific)

5. ANA All Nippon Airways

(REUTERS/Yaya Shino (REUTERS/Yaya Shino)

4. Emirates

(Emirates (Emirates)

3. Qatar Airways

(David Slotnick/Business Insider (David Slotnick/Business Insider)

2. Singapore Airlines

(Singapore Airlines (Singapore Airlines)

1. Thai Airways

(Thai Airways (Thai Airways)