For gamers who have been around the Internet long enough, there are few phrases* more enraging, on a fundamental level, than "yes, I'm a girl." These four simple words have instantly shattered the reputations of countless "gamer girls" who may otherwise have avoided my fiery, spewing fury. The only (ONLY) situation in which any female gamer should ever utter these words is immediately following an inquiry of "are you a girl?" from some other person, perhaps confused or startled by your voice/breasts/amazingly-accurate Yoko Rittona cosplay.
*Those few being "EA buys out Square-Enix, Atlus and Capcom" "Microsoft no longer replacing red-ring consoles," and "Nintendo to devote all development teams to Wii Nosepicking"
This phrase, always spoken (typed) with a hint of sarcasm, a touch of "you can stop staring," has one purpose: attention. That "stop staring" attitude is usually code for "stare more, I'm special!" We live in an age of gaming; one that not only includes women, but counts them as a market share equal, almost, to that of men. Yes, many of those girls are playing Cooking Mama and Wii Fit, but these are gateway drugs. It is not at all uncommon for those same girls to borrow more "hardcore" games from friends, or buy them on a whim, and soon become entrenched gamers themselves.
The point, obviously, is that female gamers are not uncommon, and, ergo, unexceptional. Pedestrian, even. But the stereotype persists that gaming is a man's sport (or, if you ask some sensationalist reporters, "man-child"), and so these women feel they have to be tsundere about the whole ordeal. To be honest, I can't even blame them for yes-i'm-a-girl-ing, because I understand why they do it. They know it's incredibly hot to see an attractive young miss with a controller in her hands, and women never pass up an opportunity to be treated like a queen (GENERALIZATION). Many, if not most, do it unconsciously, or think they have another reason for it.
Similar to the gaijin phenomenon, girls like to be the only girl playing on the boys' team. They like being the only female in the lives of all their drooling, nerdy gamer friends, even though this delusion is often untrue. To put it more clearly, ladies don't like competition, and getting in close with "the guys" makes them way cooler than any non-gaming girl.
Of course, I am well aware of the existence of girls who play games and (!) don't brag about it. They can be very hard to notice, because they don't go around with neon signs on their foreheads. They play games, read Kotaku, carry around a dice bag and discuss all of these things on the same level as everyone else. They like what they like, and don't think it comes with a trophy and red carpet.
Gaming ladies of the world, please be more like this. I want to like you, but you have to realize that you are not alone! You are not the first girl to play Shadow of the Colossus, you don't have to be a buxom elf for guys to play D&D with you, and you do not need to let everyone know you're a girl. In fact, it's cooler when you don't point it out, because you fit in that much more easily. Using that miserable phrase doesn't make you a bad person, but it will make every gamer worth his salt in a fifty-foot radius cringe with rage. Especially the kind with breasts.