The anime is an absolute classic, and quite enjoyable to watch, despite how convoluted the plot is. I have yet to read the manga, but I really want to, considering how much more there is to it. I should probably go download that after work. :p
My reaction to the film grew more positive after seeing it several times. Originally, the bizarre ending just left me with a "wtf" attitude, and I saw it late at night, so I had considerable trouble following the mess of a storyline. But after seeing it again, it became much easier to focus on how badass it was; the awesome animation, gritty cyberpunk setting (perfectly accompanied by a great score) and the random scenes of hallucinations are all executed extremely well. The scene where Tetsuo briefly imagines a giant pile of organs slipping out of his stomach and frantically tries to scoop them back in is one of the most memorable things I've seen in a movie, and, for some odd reason, one of my favorites.