Best?
Too many different flavors.
Standing on the bridge during training exercise, I notice that our ship (CV-66) began a turn to starboard and no turn seen by escort (cruiser) close to us along the starboard.
I speak up.
"Officer of the watch, CBDR (constant bearing decreasing range) to contact off starboard quarter." He runs over, takes one look, and gets on the radio ... quick and concise call to them ... we see them turn.
Two weeks later, I find out that he credited me with avoiding the collision at sea. Nice of him, but IMO his quick thinking and comms to the cruiser is what averted a crash.
Flying:
So many, but I'll never forget one that happened years after.
In a serious meeting, late in my career, with a bunch of Navy, Air Force and Marines talking close air support and things to get better. A guy stands up, USMC F-18 pilot, walks over to me, grinning.
I recognize him ... man, it's been years!
We shake hands.
He tells about fifteen other aviators "Guys, this is the man who taught me how to fly. Without him, I'd not be here today." Wasn't expecting that. (He was one of the last guys I got through his solo during my flight instructor tour). It was one of the nicest things anyone ever said about me.
There were others, but I think the NDA is still active on most of them.