Such a landmark piece in the worlds of film, art, anime, animation, I could go on and on. As
Fools idol
mentioned above, this appeared on the scene when anything that was significant coming out of Japan in such a vein was just "oh look, they are showing the entire rest of the world how to do things the best way imaginable." I definitely felt weird when I first watched this (I think it gave me a pretty good headache) - so much to take in, the attention to detail of all the tiny elements was far and beyond anything I'd ever had seen, and mind you "modern" anime was still a pretty fresh/underexposed concept in the west in those days.
I think I can just sit back and enjoy letting the film wash over me more now, a lot more so than when it was new. In some ways it is disappointing that it's never been touched, not even close, by anything else of this nature (can you correct me, I would love to be educated). About 2 years ago, I finally read the entire mange after all of this time. Also very much worth experiencing, especially if you are any kind of a fan of this film, although it's quite different overall (and can still be confusing/off-putting, haha).
On a side note, definitely check out the film Chronicle if you haven't. It's got issues like any film, but in many ways it has felt like the closest Hollywood has ever come to approximating some of the pivotal stuff that was popularized in Akira.
If you are a fan that is interested in some of the crazy tech underpinning this film's production, you need to watch this brief, incredible analysis