My all time favourite is the classic "Battle of Britain" because it feels authentic and has some of the best one liners...
Flight Commander of the Polish Training Squadron demonstrating excellent power of command after his wards have peeled off to attack a German formation, "SILENCE...IN POLISH!".
Robert Shaw as a Squadron OC returning to base (which is full of craters) to find a number of German airmen POWs being unloaded from a truck..
"Corporal, where are you taking these vultures?"
"Officers to the mess, NCOs to the guardroom sir"
"Well they're responsible for this mess, get them to clean it up"
"But sir, what about the officers?"
"Give them a bloody shovel!"