Never cried because of a film in my life, but there is one movie that made me come close to dropping a tear, had my eyes acting up, it's called "Our boys: Outrage at Glenn ridge", it's a true story about this mentally retarded girl that got raped by a whole football team.
There is a scene were the prosecutor in court digs up her suppressed memories of the event, and she relives the rape through a flash back, she did it for acceptance and was smiling and crying through the whole ordeal, very sad.
There is another movie that most of you wouldn't have heard of called "symphony for lady vengeance" although this one wasn't sad, it moved me tremendously. There is a very powerful scene where she has to reenact the murder of a child, even though she is Innocent, for the sake of her own baby; here it is:
From the glancing shot of the actual psycho and her child, the cinematography, the grief in the parents eyes, the subliminal anger the woman expresses towards her hopeless situation, the visceral score, the crescendo, the intensely hateful look she gives the psycho in the end .e.t.c. definitely one of the most powerful scenes in modern day cinema.