A Clockwork Orange
Apart from all the unsavory violence shown this was a great film and conveyed a powerful message. Moral of the story for those who didn't get it is just like the pope said "True goodness comes from within. Goodness is chosen". Reform can only be made if an individual is ready to alter their behavior independently; virtue cannot be forced. Alex was never cured, he still possesses violent tendencies but is physically unable to act on them.
But as seen in the conclusion of the film, his suicide attempt seemed to have rid him of the psychological restraints preventing him from acting violently. He no longer reacts negatively to Beethoven's 9th symphony, therefore he no longer reacts negatively to engaging in violence.
Also shout out to Gene Kelly, I bet he hated the context in which "singing in the rain" was used in this film