My flight from Hong Kong to Saigon just jumped to mind. I flew YOW-YVR, YVR-HKG, and then had to wait longer than expected in Hong Kong because the plane I was supposed to board had hit some bad turbulence going SFO-HKG (and was supposed to continue to SGN) and had to be inspected, and possibly repaired, before it could fly again. That meant that another plane had to be assigned to the HKG-SGN flight. Fortunately I had met someone online who was going to be on the same flight, so I had someone to wait with (she was also going to be seated pretty close to my seat).
After a few hours, a plane arrived, and it was a 747, same as the original plane. However, there were barely any passengers boarding. This massive plane couldn't have had more than 50 passengers. Heather was smart and lay down in the middle seating, and while I should have done the same, I don't sleep well on planes. I do wish I'd got out the camera and taken some pictures of the nearly empty plane - just a few heads here and there.
Getting into SGN was almost immediate culture shock, especially considering the (very young) soldiers rushing to their posts once our very delayed flight arrived. Taking a taxi to the hotel at 1am or so (it was still incredibly hot and muggy, even at that late hour) let me see how alive the city was.