The first Vampire Hunter D movie made me cringe at a time or two.
Unnecessary gore and dismemberment ahoy!  Angel Sanctuary was rather
disturbing, too, for various reason.  The manga is pretty gruesome, but
there is one part in the anime that I just can't watch... Then there's one
anime movie/OVA series that I didn't get through because it was so
sickening... I can't remember the title, but I do remember turning it off
when the tentacle-rape stuff came in.  It's just wrong.  Berserk and
Hellsing are good for distrubance as well.  Hellsing is the best disturbing
anime in my opinion.  :)