Fushigi Yûgi - The Mysterious Play

This show, far and away was the best anime, and perhaps story I have ever seen. The plot is incredibly intricate, the characters (with minor exceptions) are all intricately written (There is not a single un-sympathetic character in the show), and has a soundtrack that does nothing but push the emotions shown in the show to their limits.

However, it does deal with some adult subject matter, and does some things that will make you think long and hard about it for days, weeks, even years afterwards. The plot twists usually cannot be seen in advance, save for a minute or less before they happen. Even so, there are a few that will throw even the most critical show watcher (they did me!). By far, though, the show is best experienced if you go in with an innocent mind, and let Yuu Watase do her magic... you won't regret it.