I'd have to go with Teito Klein. Frau is too much of a playboy so I only see him as a best friend who will openly tell me how many girls he's banged since his teen years, Castor is... well, a know-it-all and has a doll fetish and Labrador is too pretty for me. Mikage... I like his character (he told his best friend I love you before he actually died!), actually but Teito is the one for me. Brown hair, green eyes and a slim body? YAY. Plus, I love his tsundere-like character (especially with Frau!) and he is kind to everyone, except Ayanami, of course.