Netori - Porn and comics usually do not play this up and are not immersive enough to matter to me anyway. But very popular in games.
Corruption / grooming / whatever that progression system in Akabur's Witch Trainer was - Gradual sexual and moral degeneration of the LI, by constantly pushing her boundaries, where you had the option to go overboard, but then suffer consequences for it.
Futa - Turn off in real porn and never understood it in hentai. But Japanese VN's by Empress (Discipline, Starless) used it so often, I warmed up to it.
Impregnation and pregnancy sex - The concept needs sufficient setup through a longer narrative than porn/hentai can provide. I guess, there are comics and manga about it, but I was more exposed to it via adult games, where it is both very popular and the player has some agency in the matter (at the very least, "Cum inside/outside choices").
I'm constantly surprised by well-made games. Just because something corresponds - or contradicts - my fetish doesn't mean I have to like or dislike it in a game. However, I mainly play games for entertainment. Games are not primarily wank templates for me.
Discover as in "I didn't know I liked..." None. (Well... unless it happened and I forgot... cuz I'm fuckin' old.)
Discover as in "I didn't that was a thing." Quite a few... but the top of the list: Vore. Hard fucking pass on that one but then, that's more for you guys.