Shall we make a few recommendations?
The Great Dictator- Charlie Chaplin movie. It's his first film where he speaks. He plays a jewish barber as well as Hitler. This was actually made in 1940 and apparently Hitler actually watched it twice. Consistently good pacing, with some pretty funny jokes that hold up to today very well. The first 20 minutes are a bit slow but it gets even better as it progresses, and the speech delivered at the end is chilling, at this point it seems that he is speaking to the audience rather than characters in the movie, and it is stunningly well acted.
http://www.imdb.com/title/tt0032553/Network- This is the movie where the speech "I'm as mad as hell, and I'm not going to take this anymore!" came from. It's remarkable how current the themes in this movie still remain. Imagine Fox News x 10
http://www.imdb.com/title/tt0074958/?ref_=nv_sr_2A Clockwork Orange- I feel like you've definitely seen this, but if you haven't, put this at the top of your list.
http://www.imdb.com/title/tt0066921/?ref_=nv_sr_1Waltz with Bashir- This is an animated documentary about the invasion of Lebanon in 1982. This film I watched in school and it has stuck with me. I have never seen a documentary use such a stylish approach. If you're looking for a historical war drama, theres none quite like it
http://www.imdb.com/title/tt1185616/?ref_=nv_sr_1Barton Fink- A Coen Brothers movie about a writer who goes to Hollywood, who finds his environment is starting to feel like purgatory.
http://www.imdb.com/title/tt0101410/?ref_=nv_sr_2