If you don't mind high levels of brutality, excessive nudity, and other psychological shit, I recommend trying out this manga. It is, by far, the BEST HORROR/SLASHER manga out there (for me). The mangaka is very familiar and experienced in drawing the "ecchi" scenes, and does so while displaying a brutally shocking amount of gore for horror fanatics. Gotta keep an open mind before reading this one tho :P
DEAD Tube