If memory serves . . .
Well, I dunno. It depends on how you add them up. With Psycho, they mention his mother's death, and her lover's death. In the end, they mention about some 'missing persons' reports. As far as deaths that we actually see, there is Marion Crane, and then Arbogast. So the murders that we actually get to view, are split even. One each.
Then, do you eliminate the actual killer's, vampire's, etc . . . deaths. If so, in certain slasher horror films, like with the
Friday the 13th series, it is not all women, or mostly women. With the first one, not counting good olé mom, you have five guys, and four girls. Then the guys win it, six to four, in part two.
Vampire movies? Well, with
The Lost Boys, not counting vampire deaths (They're all guys, anyway), you have roughly six to one, for the guys. Then, with
Fright Night, bad people not counting (Again men), you have two women being killed, to the one guy. The movie
Vampires is no contest. Between all the monks, and the two to three Catholic preachers, the men win, easy.
Keeping in mind that he/she probably hasn't heard of half of what Mark listed, I can understand the question. I didn't know about five of them, myself.
Sure, there are numerous movies to cover, and I am sure many have women being killed more-so than men, but I feel pretty sure that the men are quite a bit in the lead.
You guys remember the women instead of the men, because the women are usually naked when they die.