Of the choices you listed, I hate the "women don't like porn" myth. I do know some women who think that porn objectifies women (what, men aren't objectified?), but they don't watch porn, so they don't understand just how much variety there is out there. Saying that all porn objectifies women, is like saying all Hollywood movies are violent.
I also know women who don't like porn, because they feel like when they're partner views it, they are "cheating" on them by getting off on watching other women...which is also ridiculous. I wonder how many of those women have fantasies about Johnny Depp, or Brad Pitt, or the cute guy who works at the Starbucks down the road, or whoever they like to ogle.
But there are A LOT of women who like porn. There is porn made by women, for women. There's porn that's made for couples. And there's porn that is aimed at men, that women like to watch, too.
I hate this myth, because it just reinforces gender stereotypes and double standards. It does nothing but make women who do like porn, and don't realize that they're not alone, feel guilty about it, or like they're abnormal.
In fact, just about any myth that says, "Men like this, women don't, and they only do it to please men," makes me crazy. Such as: women don't like anal, women don't like giving blow jobs, women don't masturbate, women don't have high libidos, women don't want casual sex, they always want to be in love, women who have multiple partners or lots of sex are sluts (but hey, I embrace the term "slut," personally), women don't want men to cum on her face/breasts/ass/in her mouth...I could go on and on. These are all so common among sexually repressed or uninformed people, that it's just shocking.
There are some regarding men, too. For example, any man who wants anything done to his anus during sex is secretly gay, men who want casual sex are all jerks and have no respect for women, and bigger is always better. I'm sure there are more, but I'll stop there.
You know what? Sex myths all suck!