Most Gamers Are Male
Guy 1: "I-I only play it for the fighting. I-I appreciate the expansive multi-tier environment, and the sixteen characters...the pixel-shaded bump-mapping...and the rich plot development. Seriously, why else would I play it?"Guy 2: "She kicks high."
The primary demographic for video games is still males ages 15 to 25, with everything that implies. This is slowly changing, but video game developers and publishers still do quite a bit of Pandering to the Base. Expect Fan Service, especially in the form of Stripperiffic female characters, gratuitous violence, and concepts that are oriented more to explosions and racking up a high body count than plot or character development.
People who are not males between the ages of 15 and 25 can still enjoy games, but they should always keep in mind who the publishers are aiming for, and adjust their expectations accordingly. We're getting there, but it ain't Shakespeare yet.
This is all quite interesting, considering the fact that recent studies show that at least half of gamers are indeed individuals lacking a Y-chromosome. Maybe this is really explained by Most Writers Are Male (Although considering how many women work in the games industry, who knows).
Another interesting note (from a study) is that while about half of gamers are female, they usually play different types of games. That's not to say only guys play Halo, or only girls play The Sims, but clearly all this data means that a simple pattern isn't forthcoming.