I'm not necessarily a fan of all the games I mention below (except GGGB), this is just a simple list:
-The truly amazing, brilliant GOOD GIRL GONE BAD (sorry not male protagonist, but cannot be left out). I have not seen anything as fucked-up in terms of cucking and cheating in any non mom/son story. You need to try it. And the English is excellent. We're talking about a well-written story, truly perverted, manipulative, addictive. I usually skip dialogues in porn games, as they are most often awful, even when written by English natives, but this game is different. You'll get a boner from reading the dialogues, I can almost guarantee you that. And so there is a specific NTR scene towards the end, following your boyfriend's dad route.
-KIRSESS: Hosting the Quarterback, and about 8 other VNs centered on betraying mommies, very short (or incomplete), but also really lame and dissapointing in the very few renders per panel they offer, characters not looking at either POV MC or each other, poor posing, and somewhat repetitive storylines. The best IMO are (from most fucked-up after Hosting the quarterback to less fucked-up)
Cool mom Sophia
My mom is a meteorologist
My mom is a model (probably the best quality VN so far).
Then you have Desi Milf seduction, Mommy's secret, Mommy loves your bullies and Bully gets to spend the night. There are a couple of other VNs, but not good enough for me to keep and remember.
-Ana 1 to 3 (used to have an effect on me, but not so much now, rendering is really poor, RPGM nerve-breaking, English horrible)
-Because I love her (its ok I guess, pretty vanilla)
-Elena's Life (there are some cool cucking/cheating moments in this otherwise fairly annoying RPGM, and the latest update has an NTR scene with cucked husband on drugs and forced to watch.)
Other games I had in mind were already mentioned (The Tyrant, etc.)