Any novel or manga with the MC commiting incest. Don't let it only be a smut, there at least has to be some plot and depth to it. Monogamy only, any harem shall not be accepted. >: ^) Anything but yaoi.
I already dried out all interesting incest in nhentai, there's also hitomi and all those other sites for less known stuff. Here's the nuke code. 173808
Angel Sanctuary is an older shoujo romance manga. Expect plenty of drama along with plenty of twists and turns. Candy Boy is a yuri manga between two twin sisters. A lot more easygoing. Sore wa Totsuzen, Unmei no Aite ga has four parts to it, and only the first part which is exactly one chapter has the couple being a brother and sister. Still though, it was really sweet.
If a novel or manga has incest it's already useless to ask for quality story. There's quality stories and there's stories with incest, you have to choose one or the other.
That's quite the stereotype. Obviously you haven't read enough or at least explored the genre enough. Horrible judgement, and go read more lol. Just to clarify, u know how it works right?