The basic story itself isn't all that original, but the way it's presented is fucking awesome! It reminds of a David Lynch movie, but actually making sense in the end or of something from Hitchcock, but with an actually decent ending.
It's not something incredible, but it is a great thriller. One of the best of it's kind. And what makes it even better is that there are so few titles like this in the anime world. The only one I can think of right now is Monster. I know that Monster's plot is very different, but I was basicly just thinking of the kind of atmosphere this title has. And while Monster is great, I think this is even better.
The animation wasn't good for being a movie, even if the director did use it very wisely throughout the movie, which makes it still get an upper-avarage from me.
The sound, while it was good, wasn't anything to raise your hats to in itself. But it was used soooooo great. It really added to the creepy feeling. The voice actors did an awesome job here. There wasn't any voice I particularly fell for, which actually made it kind of better since they acted so damn great.
The character start of at being decent but as they decend into the spiral of confusion and insanity, they all grow. We get to see the depravity of each main character. Most anime tries to bring out to good in every character, even the villains, but Perfect Blue just brings the characters deeper into it's spiral of insanity, and I love it. Although I've seen characters done way better in anime movies. Tokyo Godfathers (another Satoshi Kon title) instantly comes to mind, where the character are made and developed a bit better. And while the villains worked great, they had some pretty lame reasons when you actually think about it.
It constantly made me feel creepy, hell, even scared most of the time. But it also made me feel depressed, which is something hate to feel when I watch something. I like sad and bittersweet things, but I have a hard time stomaching deepressing things, which is why it doesn't get a higher score.