|I don't know if it was mentioned, but in Elfen Lied, the little girl was raped by her father. Thankfully (for me at least) nothing was shown except a short flashback... wait... maybe there was something shown, like the girl being told to bend over and her crying. Fucking twisted, but a great manga overall.
Spoiler (mouse over to view)
The main protagonist (his name escapes me but it's a generic manga name) also end up with his cousin in the end. It may be ok in some countries, but still incest where I'm from.
Don't much care for incest unless it's a sub-subplot or has an interesting story behind it. Not that sick crap like everything Twincest scans do or hentai. Just not my kind of entertainment.
Oh, and in B Gata H Kei there's a sister with a brother complex. Dunno if that counts
That's all I really know.
Stop mailing me. I don't even open them because I don't care.