70+ movies that messed with my head (or at least made me think)

I absolutely love films that offer some mental exercise. I also love lists. So here, a list of films that offer some mental exercise -- whether they're mystery, sci-fi, romance, or even comedy; whether they're good or bad or ugly. I've added my own amateur comments for fellow amateur viewers. :) Also, despite its length, this list is far from definitive -- Shutter Island isn't even on it. With your recommendations, who knows, I might make a Part 2.

Here goes. My top three:

1. Coherence
• Quick synopsis: A dinner party takes a turn for the bizarre when a comet passes close to Earth.
• Keywords: Schrodinger's Theory, doppelgangers
• Quick review: This neat little low-budget gem is easily one of my favorites in the mind-fuck category. In turns cool and claustrophobic, chilling and exciting, it poses both mind-boggling questions and moral dilemmas that last long after viewing. Supreme goosebumps delivered.
2. Primer
• Quick synopsis: A group of friends invent a time machine but soon face consequences that change their friendship and their lives.
• Keywords: time travel, friendship, secrets
• Quick review: Another low-budget film that has become a personal favorite, mostly for the sweet, sweet complexity of it. I really have a thing for movies that make me want to view it a second or third time (with pen and paper in handy just to make a chart of the plot) – and with this one, a second viewing is definitely required.
3. The Prestige
• Quick synopsis: Two competing magicians try to beat each other with escalating tricks that affect their personal lives.
• Keywords: magic, rivals, love
• Quick review: This is my favorite plot-twist movie so far. Sleek, simple, yet effective story-telling, great acting from a great cast, and refreshing plot devices that are far from overused.
  The rest of these titles are in no particular order.