Two pre-AH memories moved me:
First, when I was a training in AW, teaching a younger guy some basic ACMs and answering all of his questions, finding out through conversation that he was having a hard time because he had C.P.
Second, the first time we got any type of Vox/Voice, flying around The Kraits, who were in Spitfires, and listening to them speak with British accents. It doesn't get much more immersive than that.
In AH, I've had numerous great fights, with a lot of films of some real twisters and back and forth battles. I do enjoy when I get the 1 or 2 turn kill on an overshoot. However, for me, the best memories are now the laughs with the friends I've made, both newer since I started AH, and older, such as the remaining Nomads and AWers.