Dokushin Apartment Dokudami-sou

Both go over the top when it comes to fan service and raunchy humor 

These are some of the most bizarre, disgusting, and stomach turning anime you will ever see! Both feature some incredibly dark and sensitive themes that's sure to make most viewers feel incredibly uncomfortable. Shoujo Tsubaki has gained quite the notoriety in recent years due to multiple Youtubers making videos on it and because it's readily available on Youtube. Dokushin Apartment is a lot more obscure and harder to find but you should totally try and track it down if you're interested in seeing just how weird and explicit anime can get!