Miyazaki is part of the top four greatest animators of all time (Walt Disney, Frédéric Back and Norman McLaren being the three others). This movie, his second full-length feature (Castle of Cagliostro being is first), is proof of how immense his talent is.
The storyline is great, the voice acting is marvelous (especially in French and Japanese — you have to hear Nausicaa's scream when her wounded feet enters a lake full of acid, it's the best pain scream I heard in cinema to this day) and the animation is magnificent. Keep in mind it was made in 1983-84, before the advent of computer-assisted animation, so it isn't as smooth as more recent productions, but it's still amazing to behold.
The music is a mix of classical score and synth music, which was quite popular back in the 80's, and is perfectly suited to the movie.
Most important, Nausicaa's character, the driving force behind this movie, is just amazing. Her courage, intelligence, kindness will touch you (unless you're cynical and feel nothing for nobody but yourself), as will her quest to save the world.
A must-have for animation fans.