Either Shoujo Sect au Rin: Daughters of Mnemosyne. Shoujo Sect is zaidi sex-based sexy and Rin: Daughters of Mnemosyne is like stereotypical au mainstreamed sexy.
3 sexy men from Real kwa Takehiko Inoue. This was probably the saddest manga I've ever read in my life. I cried in every volume... :( But it's a fantastic read!