I have 15 GB of Hentai mangas in a folder on one drive. There are no movies there unless they're related to a particular artist. That folder in particular is split up by Artist/Circle, Doujins, English Translated (Disorganized), and Japanese (Disorganized). Eventually I want everything to be organized by artist with some means of subdividing/finding doujins as well.
I also have a 3.2 GB folder for just straight-up animated pictures, which is 95% hentai. That one has various subcategories, from tv, to video games, to hair colours. eesh...