I second Ubel Blatt and Dendrobates

Also - Akame ga Kiru! and maybe Gangsta.

bumped 😎

second:
berserk
ichi the killer

shamo - everything you want, though it doesn't get to you as much as berserk for example

[img]http://www.nodiatis.com/pub/19.jpg[/img]
[img]http://www.dragonflycave.com/wpay/alakazam.gif[/img]

Fukigen Cinderella disturbed me , but then again I am a girly girl but it seemed disgusting to me
Litchi Hikari Club is mega disturbing , I wanted to puke in the first chapter

Recommend me horror , yaoi and shoujo manga please 😀

Shamo ? Edit** Already proposed
Sun Ken Rock ?

Both are immoral, both touch rape but no as its main theme.

Fire Candy - Prostitution, Drugs, Violence

[img]http://vdexproject.net/p/46642/partymini.png[/img]

bumped 😎

maybe Shut Hell

bumped hehe

Zetman Maybe? it's more like berserk fantasy, with monsters and shit, but there's "rape" in it and gore. but maybe not exakly what your looking for.
Fire Candy
Jack Frost - no rape but good stuff
Deadman

Call of Duty. The attacker Ghost is100%pervert! The plot is military based.

Wow, even though I see answers here for 2013, it's still useful 😛 😎

Don’t believe in the me that believe in you, don’t believe in the you that believes in me, believe in yourself who believes in you!

all these manga titles contain

sexual abuse, pederasty, and child rape

Momo to Manji
Tourou no Ori
J no Subete
Nii-chan
Zankoku na Kami ga Shihaisuru

but personally the last one is the most disturbing.