According to Oxford Dictionary, 'profound' as an adjective means "(of a state, quality, or emotion) very great or intense," which sounds just right. Derived from Old French 'profund' and from Latin pro 'before' + fundus 'bottom,' the word was used earliest in the sense of "showing deep insight." That's what a good movie does. It demonstrates a deep insight into human nature.
It makes us question the life around us, and urges us not to take anything at face value. But once in a blue moon, there are great movies. Movies that are more profound than others, because they have that magical technique. Let's take a look at some of them that were produced in this century, shall we?