It's interesting who, and what gender each culture/animal we value. This graphic video (seriously, warning, graphic) shows, the female gender is valued for it's birthing ability (male chicks are grinded alive)
And then you have the flipside in the japanese culture, women are regarded as lower than men (because there is a limit on children you can have, and men can carry on the family name while girls can't), and some of which are abandoned for that very reason
So that leads me into what us as transgender autogynaphiliacs see as desirable in women? If men are stereotypically regarded as the stronger, more in control gender, what could we possibly see in obsessing with the female species?
Well, some don't see women as the weaker sex. In fact if you look at sex, men can hardly give their penises away, but women can easily charge for sex. Look at the porn industry, women typically can make nearly $1k for a day's work (and don't really have to perform sexually, just act and look pretty). Men on the other hand are lucky if they make a couple hundred bucks, and nothing like a bunch of hot lights and cameras pointed at you to make it difficult to not only get hard, but stay hard, and abstain from premature ejaculation (and cumming hard for the money shot). Lots of hookers in any major city, where are all the men street walkers? Ever been on craigslist, there's about a 50:1 ratio of men to women, you have to wonder how there's such a shortage of women if statistically there are more women in the world than men.
So do we desire the vanity of beauty, do we desire to be admired (and not necessarily sex, it can be quite nice to get compliments on being pretty from an online photo of your femme self). Do we simply enjoy the feeling of the clothes? Are we subliminally channeling pornos we snuck watching as a kid and trying to live out those fantasies (us as the lead role)? If you've ever browsed photos of transgender folk on any forum (message boards, flickr, etc), there's no shortage of crossdressers wearing french maid outfits, lingerie, etc.