Definitely not everybody's movie - but terrific for me. The black and white photography creating a kind of objective atmosphere as well as some extremely claustrophobic moments; the interlocking between pictures, light and sound-related score is creating a perfect audiovisual unity.
This is a film about the pain that accompanies passion and the fine line between madness & genius. The protagonist obsessive mathematician Max Coen who's success comes hand in hand with his demise. He's desperate to know a certain truth but he brings great pain to himself in search of that truth. The ending is beautiful. Pi isn't about uncovering the secrets of the universe, it's about learning to live without them.
In overall bleak picture, it manages to shine somewhere between mathematics and numerology, between visions and a headache, between spirituality and science to conclude it with the basics of crossroads between life and death. And it's all done through a spiral, numerical nightmare in the edition of independent cinema aesthetics and paranoid fiction, which leads as to Aronofsky's greatest accomplishment.