Haruka: Beyond the stream of time, this made my fave list because it is quite similar to Fushigi Yugi. Fushigi Yugi in my humble opinion is better because the character development is a little clearer. In both there is a girl who goes to another world and she has a select number of warriors...reverse harem fantasy for the win.
Kyo Kara Maoh, I love anime where the character goes to another world. But getting flushed in a toilet and ending up there...awkward...this anime is awesome because the characters are well written and the concepts seem backwards...there aren't many female characters and homosexuality is an acceptable form of life and hinted at throughout.
Petite Princess Yucie, a sweet anime about a girl that looks 12 but is actually 18 years old. She goes on her own personal mission to resolve her issue. The anime world is composed of many parallel worlds to each other.