This gets greater every time I watch it.
Most music videos are considered 'great' because they have professional artwork and are packed full of eye candy, or their animation basically sucks and the reason they receive acclaim is because of the music it's animated to.
This, on the other hand, is unlike anything I've seen. Neither the artwork nor the music is particularly impressive, yet both fit together so wonderfully. After a while, you don't see lines on a screen or hear a person singing a song anymore. Instead, you witness a powerful metaphor.
The song by itself pretty clearly portrays the kind of mind-manipulation that goes on in society, where so many people spend years developing the same interests and talents, not a single person standing out from anyone else, and they grow up just to send their children off to be slaves to the common mindset of the ideal lifestyle.
The animation visually portrays everything that the song does very clearly and brings it to a new level all at once. The whole idea of the cookie-cutter society is very crude, mostly black and white. None of the sparingly-used colors ever deviate from the green, pink, blue, and yellow. Everything seems pleasant, but you slowly begin to realize how manipulative this world is, as the music and the artwork both get creepier and more intense. Even the fact that the animation loops contributes to the message and the mood; every time a shred of creativity tries to pave its own path in life, it is terminated, and the cycle of mediocrity repeats as if nothing ever happened.
Something the song itself didn't really suggest that the animation did was the idea that being unique was simply not permissible. People are meant to have different opinions and goals from each other, but the education system seems to lead many into thinking that the only way to have peace is through sharing opinions with the rest of the world. Those who dare to be different are rejected--or worse, they are severely punished.
It was also only through the decisions with the visuals of the story that I really found meaning in the 'boxes' of the song. Everyone started out with round faces, which could very easily represent freedom, just as a round ball or balloon is free. But all the adults with the box-shaped heads seemed very restricted to their brainwashed lives, none of them truly happy, their smiling faces deceiving. And I personally loved the touch of the one student, realizing while at school that he was contained in a little box.
Of course, I could be reading too much into this, since you made this in a state of insomnia. But this is still going straight to my favorites.