You can name as many as you want, I just wanted it to at least be three, to see if any types have common favorite characters.
Well that makes things significantly easier.
A non-comprehensive list in no particular order:
L - Death Note
Hei - Darker Than Black
Johan - Monster
Alucard - Hellsing
Tachikoma - Ghost in the Shell
Simon & Nia - Tengen Toppa Gurren Lagann
Mion - Higurashi no Naku Koro ni
Mustang & Alphonse- Fullmetal Alchemist
Madarame - Genshiken
Chihiro - Ef A Tale of Memories
Nagi - Mai-HiME
Nodoka - Mahou Sensei Negima