Back in 1977 I had a motorcycle accident. As I was sliding across the road, everything slowed down and my life did, indeed, flash before my eyes. The experience at that moment was remarkably peaceful. To me, that is the classic near-death experience. Normality returned when I stopped sliding and realised I was OK and unhurt (full motorcycle suit, gloves and boots).
I had been overtaking a line of traffic slowly, picking off each car in turn. I was doing 40-50mph. I must have failed to see that the particular car I was overtaking was itself lining up for an overtake because it pulled out unexpectedly and my front wheel hit its rear offside bumper, which threw me off. Me and my bike slide across the oncoming lane, coming to rest in the oncoming lane's kerb. Obviously, if there had been any oncoming traffic there would have been a different outcome (but I hope I wouldn't have been so stupid as to try to overtake between oncoming traffic).
For those that haven't experienced it, when someone says that 'their life flashed before their eyes' it is like being in a video presentation of significant moments in your life. Each 'slide' in the presentation only lasts a fraction of a second but long enough to be able to recognise it. Perhaps 15-20 of these images occurred. The 'slow motion' aspect is also interesting. I must have been sliding across the road for no more than five seconds but it seemed like 10-15 seconds and, as I said, very peaceful, as though someone had turned the sound down and isolated me from all that was happening around me. If that is how the mind prepares one for death in exceptional circumstances, I recommend it!
That's as close to death as I wish to experience until my time is finally up.
p.s. My bike was a Honda 250 G5. I can still remember the registration.