Flew from Adelaide to London Via Sydney and Bangkok.
Longest series of flights I have ever been on, and pretty much the longest you can do anywhere in the world, the USA and South America are both closer.
Got business class to Sydney (2 hours, 737-8), then economy to Bangkok (9 hours, 747-4), then economy to London (12 hours, 747-4). Allowing for flight changes this equals about 26 hours on planes or in airports.
Bangkok airport is enormous, too big for them to put anything of real intest into it. There were almost not people there and the corridors are huge. To make you walk past the various shops you get off the plane on the 3rd floor, walk all the way along a corridor, go up to the 4th floor, walk all the way back to where you came from and go down a ramp to the same gate.
The plane you get back onto is the same plane, they just make you all get off so they can clean it etc, which is much needed to stretch your legs.
Fortunately my Qantas Frequent Flyer status allows me to use the first class lounges in all the airports, so thers no shortage of food and drink on offer in Adelaide, Sydney and Bangkok.
On the various flights theres no shortage of food either, Adelaide to Sydney was business class so it was a full meal with the bakery basket and whatever else, Sydney to Bangkok was 2 full hot meals, you get a menu with a couple of choices. Bangkok to London was also two hot meals, the breakfast at the end was very good with an omlette.
The inflight entertainment system worked the entire way, I watched too many movies and a heap of episodes of the family guy.
To my knowledge I did not sleep at all on the plane, so this meant I was effectively awake for close to 38 hours straight.
Highlights were flying over Russia, Turkmenistan and the Caspian sea at night with a full moon, you can see lots even in the dark out the window.