Rear Window.

Everything about that Hitchcock masterpiece is just perfect in my eyes.......well, nearly everything.
At the end of the film the killer, a man so terrifying in that he has already killed his own wife and, in all probability, has cut her body up and packed it in a suitcase, is on the verge of killing our hero. But he is fended off for long enough to allow the police to get there in the nick of time.
And how is this monster, this most horrendous human being, fended off? With a flash-bulb....that's how. Flashy flashy aaaarrggghh my dainty pink eyes!!? Nope, it doesn't sit well with me at all.

I've waited thirty years to say that to someone.
Thanks.