So, here's my Worst Flying Experience tale. It pales in comparison to your stories of defying death on Third World airlines or taking hard landings with white knuckles, but it has its own unique flavor of misery nonetheless.
I was in Hawaii for an academic conference. More accurately, I was ready to jump off a bridge after my first year in grad school and I used the conference as an excuse for a vacation in Hawaii. My inbound flight was uneventful, as was my stay.
As is common with Hawaii-US Mainland flights, my outbound flight departed around midnight. Departing at midnight local time puts one in the continental US around midday the next day. Of course, leaving at midnight means that everyone on the flight immediately goes to sleep. Among several hundred people on a full 777, there was not a soul awake 20 minutes after takeoff except for the flight attendants. And me. And the person sitting next to me.
I am going to try to be delicate here.
I had an aisle seat and the passenger to my right was a large (severely) developmentally disabled boy of about 15. His handler, for lack of a better term, sat to his right. With an attitude that unmistakably said "I have been dealing with this kid 24-7 for a week and I'm goddamn tired of it" and without so much as a word to the kid, the handler put on a sleep mask, inserted earplugs, took a quantity of prescription sleeping pills that I imagine would adequately tranquilize most zoo animals. She immediately fell asleep.
This confused the kid. He did everything he could to get Mom/Handler's attention but she was out cold, clearly with the intention of not having to deal with him. So he turned his attention to me. Intermittently for the next eight hours, I was slapped, poked, headbutted, and unintelligibly slurred at by a child with some obviously extreme developmental handicaps. I tried talking to him to no effect. So for the duration of the flight, every time I tried closing my eyes, reading, or listening to music I wouldn't make it a full minute before he started doing something that involved all or part of his body from striking mine. I am pretty sure he shit his pants around hour six.
The icing? Since everyone on the flight was asleep, the attendants did not bother changing the in-flight film. Thus Miracle, the jingoistic Kurt Russell film, played three times in its entirety. An attendant offered me headphones for the audio, which I politely declined. I was the only way I could think to make the experience worse.