I'm pansexual so what attracts me to the various gender identities is personality first, then body. For males, having grown up with them; I find them easy to relate to. A man's world is so straight forward and many present themselves as such, which I love. It helps when they share in your interests (of the nerd persuasion in my case). Like many of you have said, I just feel more feminine with a man and the often candid interest in me really boosts my self-esteem xD Body wise, I do like a muscular form and them being taller than me but my standards are very simple, if not easy. Winning personality and little body hair/well groomed in places, and you're good in my books. Lots of bonus cookies for mutual interests.
With women I do feel a bit more top I guess, for a lack of a better term. Though I do physically like women more but personality wise I've become much more strict. I'm not quite ready to call myself a tomboy but if I end up feeling that way more often than not, then it's a turn off. I want to feel equally feminine in a relationship with women. Where we're both good girlfriends having a strong co-dependence with each other. With that ability to communicate comes a wider range of emotions to read, making problem solving far more complex. Makes it feel like you're walking on glass at times. When it's good it's cloud nine, when it's bad it's...well hell =p