For me, Kyuuketsuhime Miyu is definitely one of the mangas you're searching for. One word that I would use to describe the style of the artist is... graceful. I especially love how Kakinouchi Narumi does Miyu's hair.
"The only ones who should kill, are those who are prepared to be killed."
I'm suprised nobody mentioned Pandora Hearts yet. The mangaka especially is very good at the anatomy of the characters and the character designs are just flawlessy beautiful. <3 And the way she works with the panels and such is just great. I really recommend it.