One day I was standing in the street talking to a friend that was inside his car... I hear a rumble, and look up to see an F-16 flying pretty low at a GOOD rate of speed. When he got over us, it was so loud I couldnt hear a word my friend said. That was cool.
Then there were the ROTC days at Ft. Dix at the obstacle course. Sitting at the top of the cargo net climb for about 2 hours with kc10's going over your head right after take off gets a little ear piercing at times.