'Requiem for a Dream'

I couldn't find the exact scene I wanted but thought this trailer resembles it very well. There is a sequence toward the end of the film which I believe is edited superbly and is purely emotive. There are sharp fast cuts between all the main characters in the film that expresses their downward spiral to toward the low depression of life. I personally think this is one of the greatest films ever made and by a director I really admire, Darren Aronofsky.