A similar scene that always gets me was the Marsellaise (sp?) scene in Casablanca.
Facoid, most of the actors and extras in that scene were really refugees from the Nazis. So their defiance was real, not acting.
Yes, that was the one I was going to cite. I didn't know that about the characters being refugees, though. Maybe that's what makes it so touching. You can't fake that kind of intensity.