In my opinion, the S movie stands head and shoulders above the other two in almost every way. I'm glad that the focus is on Luna instead of Usagi. Not that I dislike Usagi (quite the opposite), but we get plenty of her in the TV series, so it's nice to see something different. Also, they managed to fit quite a bit of stuff into a short running time without making it feel too rushed. The story isn't the most original or innovative, but it still hits all the right notes.
Speaking of hitting all the right notes, the best thing about this movie is the music! It uses all the various musical cues to great effect, without going too over-the-top. My favorite is the beautiful, heartbreaking theme used for Luna-- I cry when I listen to it. The music does a great job of punctuating and enhancing every scene and without it, I don't think I would have enjoyed this movie so much.
