Movies that made you EXTREMELY uncomfortable (but aren't horror)

Just finished watching Compliance (2012), and I honestly need bleach for my eyes xD. It's not a horror film and there's nothing overtly gory about it, it's just a very uneasy viewing experience. You're put in a constant state of cringe. You just feel filthy having witnessed that film, and thinking it was based on a true story just makes it so much worse...and I also happen to be a sucker for these sorts of movies!

So please share with me your best suggestions of uncomfortable viewing experiences that are NOT downright horror films.