I'll add to the list as well:

Androgynous: Expressing and/or presenting merged culturally/socially defined feminine and masculine characteristics, or mainly neutral characteristics. May or may not express dual gender identity.

Bigender / Dualgender: A person who possesses and expresses a distinctly masculine persona and a distinctly feminine persona. Is comfortable in and enjoys presenting in both gender roles.

Gender-Bender: A person who merges characteristics of any gender in subtle ways or intentionally flaunts blurred stereotypical gender norms for the purpose of shocking others, without concern for passing.

I also think this comment is worth noting, except its author did not offer a name for it. Maybe there are such persons along the entire gender continuum:
Quote Originally Posted by LilSissyStevie View Post
One group you almost never hear of on these boards is the group that doesn't crossdresses at all because they feel no hope of looking like the opposite sex or even the desire. Feeling it suffices.