If you haven't seen the movie, make sure you get the 2001 Pioneer version, which has vastly superior dubbing compared with the original English-language version from the '80s. The DVD also has helpful bonus features, such as graffiti translation – which was done in the English manga version. It will definitely help the uninitiated follow along (well, to a point...)
I remember watching the first video version back in the early 1990s, and not knowing what the hell was going on at all. This was, mind you, before the manga was available in English – in fact, Akira was largely responsible for the surge in interest in manga in North America at the time. Intelligible or not, the film was still a revelation for any kid hitting puberty in that pre-CGI era. And it's a shame that mature animation still isn't a mainstream reality outside of Japan.
In defense of the old Akira video, the guy who did the voice of Kaneda was the same guy who did the voice of Leonardo on the original Ninja Turtles cartoon. Pretty cool. Also goes to show how insular the voice-acting industry was at the time. Even as a kid, I remember thinking, "Hmmm... Starscream sounds an awful lot like Cobra Commander..."