I do not not exactly by what you mean by dirty anime, but I will try my best in answering your question. For really eechi and percerted anime, try this: Kanokon, KissxSis, School Days.
For really messed up Anime, try: School Days (really messed up), Wlecome to the N.H.K. (Not that messed up).
For a really gory, sad but romantic anime, try: Elfen Lied
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Inuyasha one of the best animes I have seen or are you looking for a different anime?
Rosario+Vampire Gakkou no Kaidan or Ghost Stories(in english) Pretear
Nightwalker or Vampire Knight, depends what your looking for, there are a few if you have a good mosey around.
Osamu Tezuka