Just as Lightning said, Yuu Watase is awesome. :3
She has an awesome way of telling stories... Her way of putting twists in her stories is amazing. And her artstyle is gorgeous.
It's too bad she's in such bad health though. I would love to read the continuation of Fushigi Yuugi Genbu Kaiden (which is my favourite Manga)... Compared to the original Fushigi Yuugi, Genbu Kaiden is much darker and mature.
My other favourite Manga-ka, is Yukiru Sugisaki, the author of D.N. Angel, the Candidate for Goddess, Lagoon Engine (Einszats), Rizelmine and what not...
I do prefer the style she used in D.N. Angel and the Candidate for Goddess though. The characters aren't so... childish. And the amount of detail is.. wow.. I wish I could draw like her. xD But the closest I come to her style is the Animestyle of DN Angel/CfG.
It's too bad she has a habit of leaving things unfinished and starting new things... But you don't hear me complaining,
I do the exact same thing. XD
I also think that her style was at it's best (to me anyways) in the Ice and Snow Arc (Volume 6-9), it was very nice in volume 3-5 as well. But in volume 10-11 (before hiatus) and then 12-13 (after the hiatus) her style changed a lot. Not that I mind. :3