First-In 1987 I was on an Ansett Airlines flight internally in Australia. There was a violent thunderstorm and we circled for over an hour trying to avoid landing in it. Unfortunately we were low on fuel and had to land. We dropped like a rock during a rapid decent for landing with lighting striking all around us. First time I was scared on a plane.
Second-Around 1994 I was traveling from Newark NJ to Hong Kong via Tokyo on United. We were around 2 hours outside of Tokyo finishing dinner service when our 747 started going up and down like a yo-yo. A food cart left the floor and was toppled, several people including flight attendants hit the sealing, food was spilled all over the cabin and I think I actually lightly pissed my pants. I remember my heart beating 100x's a minute. the turbulence lasted around 45 minutes and when we landed an ambulance greeted our flight. This become a common problem flying into Tokyo over the 20 flights I took. Always some turbulence in the same area over the Pacific.
Third-1994 My first flight into Hong Kong and Kai Tak airport on a 747 at night. I was alone and no one warned me about this. As you approach the airport, the plane needs to maneuver between all the mountains and the pilot cocks the plane on a 35% angle with sharp turns. I was against the window and as we kept turning and going lower, I began to see people in their apartments as the building were closer and higher than us. It seemed like forever and just before we landed, the plane straightened out. My hands had dug so hard into the arm rest. I was shit scared.