Hahaha. Oh, man. Shoujo. I don't read traditional ones so much anymore. I know I have liked some.
I read Sailor Moon back in the day (Yes, Mixx Pocketbooks), but again the first couple of volumes pwn the rest. The creator got so sloppy and rushed her ideas.
Let's see. Think, Tanuki, think. Tokyo Babylon wins for its ending. Despite the problem some people have with the ligth Shounen Ai, the views on society and the portrait of the times is great. Like I said, despite the silliness, it wins. MARS is good, but I like the atmosphere in the beginning better than the ending. Fruits Basket was enjoyable, but I had problems relating to the main character Tohru, which really took a lot of the fun out of the series for me.
I have read a lot of CLAMP Shoujo, but most of it is like alcohol - an aquired taste. The exceptions to this rule would be Tokyo Babylon and Clover - which stand elegantly in their own right. X is all right, and while I am a fan, it suffers from commercialism and wishy-washiness and being jam-packed with more characters than CLAMP can appropriately develop.
On the other hand, I dislike Yuu Watase stuff. So many people love them, but I just cringe. So sorry, Yuu Watase fans. Nothing against it, cause I read from beginning to end, too. Her ideas are fabulous, her main characters make me want to gouge my eyes out. There's just his...lack of finesse in main character execution...Miaka, for instance. Watase's best series that I have read was Ceres, but even that suffered from some fatalistic character problems and over-the-top drama. (And I like over-the-top drama, but again - execution problems.)
I guess in the end...I'm more of a Shounen gal...