If you hated it, it's probably because you didn't understand it ...

Rating: 8/10 (3 April 2011)

... and that's by design.
The central theme of this film is so disturbing and distasteful that it had to be communicated in the most subtle and subdued way. It had to be this way to avoid the box office-killing NC-17 rating, and also to keep scores of people from being disgusted and turned off. Darren Aronofsky, known for his blunt style, had to resort to this extreme subtlety out of necessity, and the result is a film that is brilliant.
Now that you've had enough time to stop reading before hitting a spoiler, here is the bottom line. This film is about an obsessive-compulsive young woman slowly losing her mind. The reason: her sexually abusive mother. That's it. The incestuous relationship is only hinted at various points in the film. I noticed four, although there may be more: 1) When the mother gets Nina to lick the frosting off her finger, 2) When the mother tells Nina to take off her shirt and she yells "no", suggesting that getting undressed at her mother's command was not an unusual occurrence, 3) When Nina jumps into bed moments before the mother comes into the room asking "are you ready for me?" (this one's a dead give-away -- what else can it mean?), and 4) Spout's theory that "... coming home, still high from rolling, Nina's mom accosts her in her state and has sex with her. However because of her state, Nina is more responsive than usual because she is imagining that she is with Lily (it is later revealed that Lily never came home with Nina). That's why the shot of the mom on top of Nina is one of the mom smiling before she continues oral sex with Nina."
In ballet, Nina has found refuge from this horrific existence, which explains her obsession with her art. In the end, she cracks up from the inside, and this is what we get to witness from her point of view.