Darren Aronofsky, I guess, could be called a film genius. Requiem for a Dream is considered to be one of the best movies of recent memory (and, from what I saw of it, I can agree), and has many of the same techniques as his previous film, Pi. Pi is one of those movies that you need to see many times in order to have everything sink in, but you don't really want to see it again. The images stick in your head, and it's a subconsciously terrifying experience.
Max Cohen (Sean Gullette) is a mathematical genius. He analyzes numbers, and soon recognizes a pattern in the stock market. But that doesn't satisfy him. He keeps on going, as people want to use his mathematical abilities for their own selfish reasons. Max struggles with his various mental and physiological problems as he's working with this-so much that if you watch it once you can't distinguish between reality and Max's mind.
Aronofsky makes this movie on parking meter money (less than $10,000), yet it's one of the most stylish movies of recent memory. Shot in black/white (there is barely any grey) with a type of vision that leaves edges to the imagination, Pi works in its own little world. With a short runtime that's shorter than Dennis Miller on one of his longwinded analogies, it works. The theories that the movie puts in your head are complete bull-honky, but they're presented in a way that you can't help believing (like many people think about Michael Moore).
Well acted all around, especially by Guellette, Pi is not for everyone. There's many disturbing moments, involving brains and power tools. The second-to-last scene, just so you know, was actually done, no special effects. Overall, Pi is a very good, trippy movie that's not for everyone. But if you're game, go for it.