For a man vs women version.

Some of those are pretty decent examples but Knock Knock doesn't fit at all. It's female villains kidnapping and abusing an innocent man and ruining his life for their own sick thrill but then he doesn't get revenge at the end, they get no punishment whatsoever unlike the male rapists in this one.

What I do sometimes wonder though about is this -

Even though indeed in many films and films like this the villains are indeed usually men, and based on that reason alone subconsciously if they do all the cruel stuff to either people we cheer at their violent deaths and whatnot, the fact that...

... in other films, perhaps nowhere near to that extent, we also have female villains and whatnot and when you see THEM doing bad stuff including but not limited to killing INNOCENT people, does it kind of stop you from thinking that its just men that are all bad and do you also want these female characters to pay for what they do, including possibly getting killed in self defense?

And yet with that all being said, it still DOESN'T even remotely stop audiences in films like this from cheering gladly when such bad guys that are men get killed in revenge often in sadistic fashion, and we all feel like it is being done perfectly and in the name of justice.

Or maybe all that means is that we could look at certain situations SEPARATELY and not use one universal criteria to judge it all. The world's not perfect, exceptions may always happen however small, though we have 9 billion people on the planet.

Heck, on a totally different side, I've seen movies where (yes male) rapists not only got away with it but were forgiven and even tried to in some ways elicit audience sympathy in the process. Think movies like Stanley Kubrick's "A Clockwork Orange" (1971) or Abel Ferrara's "Bad Lieutenant" (1992) or even Mike Leigh's "Naked" (1993) where a guy Johnny, although he was flawed and hurtful to people in other departments as well, having raped a woman at the beginning of the film, was at times portrayed as a troubled and even pitiful character for whom we were meant to feel sorry on some occasions, and no one exacted that kind of violent revenge on him like in these "Grave" movies.

I think I understand full well and yes there is at least a BIT of double standard for why it IS treated slightly differently with men and women who may do same at times bad things. But I'll explain it all later.

The greatest trick the Devil has ever pulled was convincing the world he didn't exist!