I don't know if this comes under the heading of 'amazing sights' or not as my thoughts at the time was 'how stupid'.
There I was transiting from Bergen Hohne range to Gutersloh in my little Skeeter Mk12, passing through the Minden Gap with the statue of Wilhelm gazing upon me when I was passed on the starboard side by an F104, then one passed on the port side, again very close, BUT then one passed underneath and I was at 600 ft AGL.
Another brush with an F104 in Germany was so close that the I could see into the starboard engine intake and could clearly see all the rivits as the jet passed over me. It was in weather conditions that was bloody difficult for me (viz about 1 mile at best in haze) and I was low level. I had looked out forward and there was nothing there, looked right for a couple of seconds, looked forwards and there it was. I had about 1000 hours at this point. The weather was bad and I didn't expect F104's to be flying. For sure the F104 pilot did not see me. I was in a Sioux (Bell 473B1).
At RAF Ballykelly, parked outside Shackleton Hangar. Went off for military briefing. Came back and Shackleton was being prepared for ground runs. Got into Sioux and during preflight checks, Shackleton proceeded to start engines. I started up and during the run up found that I was being pushed along the concrete towards the hangar by the prop wash from the Shackleton. Frantic call to ATC and Shackleton crew throttled back and I was able to take-off. I was very close to the hangar at one stage.
I too have flown through the ring of a rainbow, it's amazing as you are in a tunnel with colours all around and outside the tunnel all is rather remote.
Was almost hit from below by a Wessex as it climbed out of a field in NI. Just spotted it's rotor blades between my feet, yanked back on cyclic and pulled up the lever and did some sort of aerobatic manoeuvre. Spoke to Wessex pilot later and he was totally unaware of that near accident as I was out of his vision behind his overhead panel.
During some very stormy weather flying up the Great Glen (southern end of Loch Ness) the wind was lifting huge amounts of water up off the surface of the loch. It was like a heavy squall going up rather than down. Turbulance was horrific and threw the AS355 in all directions.
Making a film for the BBC where it required that a Scout would formate on the port side with the camera man and maintain a safe distance during the manoeuvres involved as I flew the 'Star'in a Gazelle. At one point the blades of the Scout passed under the Gazelles blades. At debrief the camreaman liked the close up shot!! but would have prefered to have used a telephoto lens. Scout pilot lack of concentration almost was fatal.