A while back there was a bit of controversy over a Kickstarter set up by Anita Sarkeesian to fund a series of videos examining gender discrimination in video games.
The first video in the series, dealing with the Damsel in Distress trope, is up now.
It's a good watch, and highlights some of the more notable examples of discrimination in early video games. That said, it does ignore some classics such as the Golden Axe and Streets of Rage games, which always featured a lead female character fighting right alongside the men. Still, I think it's worth a watch just to see how readily game developers have jumped to the quick and easy plot device of a weak female in need of a strong male to save her.