I have not seen a film since the Matrix that completely stimulated my senses just as much as my mind. The action was top notch, acting was phenomenal, and just the overall script is as creative and intriguing as anything I have seen.
The great thing is, this movie isn't just for seeing once. Seeing it for the first time is so you can take in the core of the story. There is so much imagery, subtle clues, references, and homages both on screen and in the dialogue, that you need to see it a second time to fully appreciate this movie. After you see it the first time, I suggest everyone read all the online material you can about what to look and listen for when watching it the second time. Read about what to ponder and question, and all of the different theories of why certain names, dialogue, and images were used.
Combine the viewing of this film along with the understanding of the imagery, dialogue, etc., and you will see why this film truly is a masterpiece.