For me, it was when I went to Seattle. I live in Belo Horizonte, Brazil, and I needed to fly for about 24 hours, because of all the conecctions.
Recently, Paris-Jakarta with a layover in Doha. The total flight time was over 15 hours + a few hours in Doha.
We flew from Israel to China but we flew via Paris so it was about 6 hours to Paris then another 10 hours to Shanghai.Also the time difference confused me a lot.
8 hours from Moscow to Vladivostok. Nice trip. It can be one week if i would chose a train)
Forty hours, from Brisbane to Vienna.
My cheapest option was to buy a London-Sydney flight (I think it was British Airways), and tack on legs for London-Vienna, and Sydney-Brisbane. I recall a stopover in Singapore was involved as well. Of course, the 40 hours included waiting for connecting flights.
Now, for any stopover, I exit the airport and spend a few days in the stopover country.
The longest direct flight I've done - several times - has been 14 hours between Dubai-Brisbane, and if the flight changes at Singapore, then it's an 18-hour journey.
The longest fly I have taken was from Brasil to Australia. My trip started in Belo Horizonte in Minas Gerais and I took a fligth to Sao Paulo, we had one stop over in Chile, another New Zealand and another in Sydney and finally Perth.
