It's curious to see that Kubrick has so many scenes on this list, as most stories you hear about Kubrick is how exacting and planned all of his films were.

Speaking of improvisation: http://bit.ly/S1asAD

The drill sergeant in Full Metal Jacket was a real-live drill sergeant. They had an actor, and this guy was doing the coaching, but the actor couldn't hack, it so the real sergeant took over.

[2] Wow. That's a fucking powerful scene.