No, uhm... I think I like it when people don't want it. Or rather, when they don't KNOW they want it.
When I think about "darkest fantasies" I think about tagahanga fictions and whatnot because I'm a terrible person.
Btw, there are these pictures I saw a while back of anime girls with chopped limbs and they're tied up inside a suitcase along with their body parts... but I don't really see anything hot about that... It could be seen as a dark fantasy, though. xD