Male.
I’m male. When my wife met me she thought I might be gay. So, imagine an overweight gay-looking guy with no taste in clothes and a bad haircut. 
Cis het white middle-aged middle-class monogamous American male.
But I’m much more interesting in my imagination.
Lady here, probably obvious from my username. Lesbian, leaning toward butch. I have virtually no traditional female intetests. I’m not really gender dysphoric, but I would have liked to be a guy. Ah well, maybe I’ll be reincarnated as one.
A young man in my office is beginning to transition (M to F). When he told me my first thought was “yuck!” Not because he’s transitioning, but because I don’t understand why someone would choose to be a woman.
Guy here. My user name is a bit ambiguous. Actually it’s the name of my first dog - Alpine, spelled backwards. It sort of fits since I live way, way up in the mountains. (And I’m a bit backwards myself sometimes, I suppose. All but one of my best friends are women.)
I’m a dude
I usually use he/him pronouns. But on principle I dislike gendered pronouns and welcome people to use they/them with me, or other non-gendered pronouns if they don’t mind explaining (last time I looked there were over 40 different systems of gender neutral pronouns in English and I don’t remember most of them).
I’m a guy.
I have female parts and usually get called by female pronouns. But I’m fairly butch and I don’t particularly identify with either gender. I understand that it matters a lot to some people, but I honestly don’t understand what people mean by gender beyond the physical differences in plumbing and some average differences in personality that we call “masculine” and “feminine”. I know lots of masculine women and lots of feminine men. Most of them don’t seem too perturbed by that.
Not according to the Mabinogi, she isn’t.
Correct. This is the source of my username; and not, as many assume, the Fleetwood Mac song.
I have a penis and testicles, I don’t have a vagina, ovaries, or developed breasts, my facial hair grows out if I let it, and my voice is bass. I’ve never had my hormones or chromosomes tested, but I expect that they would probably come out with high testosterone and low estrogen, and XY. I’m attracted to women. And I’m fine with all of those facts. But I have no idea how to tell what my gender identity is.
Male here
Between my husband and me, we have two penises, four balls, and nary a vagina.
Male. Been one since before birth, AFAIK.
You inquiring about sex, or gender?
I’m a man, but I can change.
If I have to.
I guess.
beep disembodied artificial intelligence beep
As you can tell by my username, I’m a man.
Just kidding! I’m cis-gender female and straight. I’ve sometimes wished I’d selected a gender-neutral username because I’ve wondered if it affects how my comments are taken.
I hate this question, I used to make a good living as a bearded lady in the circus but then someone asked this and I replied that I generally identify as a man.
I think it speaks to the inherent sexism of society that so few people will pay to go to the circus to see the bearded man.
These days I identify as a limited liability corporation, primarily for tax reasons.