The Kid With a Bike, directed by Jean-Pierre and Luc Dardenne. This movie follows a young boy in foster care, unable to cope, and in denial about the fact that his father wants nothing to do with him. A local hairdresser decides to take care of him on weekends, as a random act of kindness, and this sheer honesty of the portrayal of this young and damaged child is truly heart-wrenching. It's depressing as all hell, but rarely are you able to see a child's performance that's this good.
Standout performance from the 12 year old actor in this film. Essentially, a story of a boy dealing with the rejection of his father, the film spends a lot of time simply following and observing him and it is his performance that helps to make you care about a difficult child who spends a large portion of the film rejecting and lashing out at those who try to help him. His eyes convey much of the anger and emotion that his character goes through. With very little music, and an almost documentary style, the film never feels like it is trying to manipulate the audience's emotions.