I'm looking for a manga with a really creepy, surreal, unsettling setting like the computer games American Mcgee's Alice, Bioshock, Silent Hill, etc.

No yaoi, yuri, gender benders, anything by Uwe Boll.

Im reading Uzumaki I think its kinda creepy i enjoy it.

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All that we see or seem Is but a dream within a dream. - Edgar Allen Poe

Imagination rules the world. - Napoleon Bonaparte

All men are born with a nose and ten fingers, but no one was born with a knowledge of God. - Voltaire

The only stuff which gave me creeps is the anime "Higuarshi no Naku Koro ni"

What I like in Trivial Pursuit style. Pick your category:[img]http://i379.photobucket.com/albums/oo233/Reid4891/Manga/trivia-1.jpg[/img]

Quote from reid1

The only stuff which gave me creeps is the anime "Higuarshi no Naku Koro ni"

This... I've only seen the anime version.
Psycho Lolita FTW!!

Point & Squirt

Just pick up any transated works from ITOU Junji, that and UMEZU Kazuo translated series The Drifting Classroom, Cat Eyed Boy, Scary Book and so on. Maybe HINO Hideshi's stuff. You also have MARUO Suehiro's stuff. Try NIHEI Tsutomu's Stuff. Theres the manga Dragon Head. You can also look into reading the Silent Hill comics aswell.