I wasn't going to bother with a list, but then actually got a bit curious as to how many I've been to, so here goes:
Manchester
Liverpool
Birmingham
Stansted
Gatwick
Heathrow
Luton
Edinburgh
Ibiza
Lanzarote
Paris CDG
Paris Beauvais
Toulouse
Reus
Girona
Madrid
Faro
Gibraltar
Venice
Rimini
Geneva
Schipol
Frankfurt
Lubeck
Memmingen
Gothenburg (City or Landvetter?)
Stockholm Skavsta
Tampere
Helsinki
Athens
Budapest
Krakow
Amman
Ben Gurion
Ljubljana
Dubrovnik
Moscow Domodedovo
Moscow Vnukovo
Saint Petersburg Pulkovo
Marakesh
Orlando
Nassau
New York JFK
New York La Guardia
San Diego
Toronto Pearson
Seoul Gimpo
Seoul Incheon
Yecheon
Osaka
Fukuoka
Tokyo Narita
Tokyo Haneda
Taipei Taoyuan
Taipei Songshan
Shanghai Pudong
Beijing
Hong Kong
Singapore
Kuala Lumpur
Kota Kinabalu
Johor Bahru
Bangkok Don Mueang
Bangkok Suvarnabhumi
Chiangmai
Surat Thani
Ko Samui
Phuket
Ho Chi Minh City
Siem Reap
Vientiane
Luang Prabang
Hanoi
Manila
Caticlan
Most of them tend to blur into one to be honest, in that I hate the vast majority of them. I love being in a new place, but I despise the process of actually getting there. A few of those are obviously just tiny, :emoji_zipper_mouth: local airports, but to fair, while they're not great as far as the facilities go, they're usually really quick to get through. I'm not going to include the little :emoji_zipper_mouth: ty ones in the worst list, just more major ones.
Some that stand out in a good way:
Singapore - Huge, yet incredibly efficient and actually a pleasant place to have to hang around for a couple of hours.
Hong Kong - Similar to Singapore really. Had a 5 hour delay and didn't mind. Free computer terminals (before the days of ubiquitous WiFi, which I'm sure it probably has for free now. Any airport that charges for WiFi is a :emoji_zipper_mouth: ing disgrace btw)
Seoul Incheon - Probably been through here more than any other. It's huge, but always get through the faff within a few minutes
Liverpool - Favourite in the UK and not just because it's the closest to me. It's small, but has everything the bigger airports have and some that they don't, including fast food and coffee chains. Always get through really quickly as well. Could do with a rail link though.
Worst:
Luton - Disgusting, vile place. Feels like an overcrowded bus station from the '60s.
Moscow Domodedovo - Poorly planned and laid out. Stupidly inefficient.
Ben Gurion - Actually a nice airport (FAB central fountain thing), but ridiculous security. I was questioned by 4 different people and had everything in my bag swabbed. Apparently, this is normal, and this was leaving the country.
Paris CDG - Honestly, fly to Beauvais and take the bus into the city. CDG is a horrible introduction to Paris, and the train ride into the city, through the gratified slums, is disgusting.