Okay, this is one of my favorites, but you should know first that this is some real Dante's Inferno, Silent Hill, Hellraiser type shit right here. There's extreme gore and some non-graphic sexual stuff, but somehow it manages to be tasteful. And it's definitely the coolest dreamscape/hellscape I've ever come across.

Some Things You Have To Live Through (http://rainylemons.livejournal.com/19743.html) by rainylemons
Length: 8,978 words
Sam wants to understand what Dean told him about being a torturer in hell. In order to try to help Dean, he needs to understand.