Looking for extreme gore/horror/violence anime.
Don't bother listing anything that is commonly mentioned because in all likelihood I've probably seen it.
If you want to compare anything to a list
https://myanimelist.net/animelist/AbDuCt is everything I've watched. Is
https://myanimelist.net/mangalist/AbDuCt everything I've read (not updated fully).
If you need any inspiration of what I like, go read DeadTube.