Two from reasonable levels of leisure-only travel.
My first was ten years ago on a turboprop from Quito to Coca (OCC) in Ecuador, not sure who was operating, for what was supposed to be a quick hop over the Andes and a canoe trip on to a jungle lodge. It was a last-minute abort due to weather (heavy fog I think), a real slam back into your seat from quite near the ground, and we had to go back to Quito amidst visions of ending up a character in Alive 2. We were told to go and amuse ourselves outside the airport and we'd give it another go in 12 hours. That turned out to be a huge blessing as the previous day Iberia had left my luggage behind on the short connection in Madrid from LHR to Quito, and with the early morning original onward flight I had had no time to go shopping before leaving for the jungle, so I spent most of those 12 hours in Quito gratefully buying underwear and contact lens solution.
Since then I've had one on approach to LHR in a long-haul aircraft maybe a year or two ago, probably BA, but comparatively speaking I barely noticed and only vaguely remember it now from knowing that, prompted by it, I told the above story to my now-husband.