I love challenging prose and along with Burroughs, Moorcock and Joyce I suppose this could be included.
It's like when I read A Clockwork Orange
for the first time as a youngster, I just couldn't get my head around it, but then a rhythm develops and you find yourself sucked in completely.
I should revisit this perhaps. I just read an excerpt online and it pulled me in again. There's nothing like breaking conventions to stir things up I suppose (not to mention the violence and abuse that Selby Jr conjures up).
Another interesting read is Kerouac's On The Road: Original Scroll - it really feels like you're whacked up on benzedrine, the frenetic pace of the writing is something to behold.