I agree with almost everyone. Preferring transgendered persons with penises instead of vaginas does not make you gay. The lines of gender and sexuality are so blurry and fluid that even the binary of heterosexual and homosexual with "bi" somewhere in the middle just doesn't do the world justice.
I think if you're attracted to someone, no matter what gender/sexuality, that's all that matters. And if you can find a lasting, loving, trusting, life-fulfilling relationship with someone you're attracted to sexually that just makes it all the better.
That's not to say that there isn't a certain type of identity or culture that you can identify as "homosexual" or "heterosexual." I'm sure if you were attracted to what the majority of society and western culture identified as "male" and you identify as "male" then you can feel free to identify as "gay." But, I know plenty of people who identify as "male" and are attracted to "male" others (no matter what the plumbing looks like) that still don't associated with gay culture or identify as "gay."
All these labels are socially constructed. If they work for you, great! If not, fuck it. I wish there was some way to embrace our attraction for transgender and transexual persons. But as it stands, the only label I know of is "tranny chaser" or other derogatory terms. Calling me a "tranny chaser" is as offense as calling a transgendered or transexual individual a "chick with a dick." She's a she (if that's how "she" identifies). Just like I'm a "he" (since that's what I identify as). I'm a "he" attracted to people who identify as "she." And if she has a penis then chances are I'm going to be as equally physically attracted to that person as if they had a vagina. End of story.