The biggest one that comes to mind was my time in the active military. I scored very well on my physical fitness tests (~320-340 for those who know), kept well ahead of my education, did everything right and was a great leader (according to my leadership). I was passed over for Ranger school 5 times this past year and each time, it was because a female who did okay (by male standards) wanted to try it out (usually failed the Ranger Physical Fitness Test on day 1). The unit wanted to be known as the unit who had the first female to graduate the school soooo badly, that they didn't even consider more then qualified people for the school. Many other well deserving soldiers got their career screwed over or stunted because of female preference. I've got so many other examples but that's the biggest one that sticks out in my mind.