120 Days of Sodom was a tough read. I don't think it's satire despite what the critics say. Marquis de Sade was literally a rapist but for some reason it is taken as being a meta-commentary on contemporary French society.
I didn't know people take it as satire. It clearly isn't. It does have some solid social criticism but Sade is in for all the dirty he writes first and foremost - any social commentary is just an afterthought.