What is the scariest manga you ever read that sends chill down your spine? I am in the moo...

Then, Tomié of Junji Ito ^^

I liked Ibitsu a lot when I read it late one night. It reads pretty much like a horror movie so I didn't get chills so much as I just liked the scariness of it (if that makes sense (=・ω・=)

I think there's also one called Jisatsu Circle that legitimately creeped me out, though I can't remember why...

first one:
http://www.mangago.me/read-manga/ibitsu/

second one:
http://www.mangago.me/read-manga/jisatsu_circle/

0.0 Mhz: hang on through that scientific talk in the first chapters and look forward to their little "field trip"... and read it at night... when it´s raining... and you´re alone at home...^^
Fuan no Tane and Fuan no Tane Plus: short and creepy urban legends

http://www.mangago.me/read-manga/the_outer_zone/

american ghost jack (〜￣△￣)〜 it's not that much of a horror but it is scary, at least to me!!

probably american ghost jack

Σ( ￣□￣||)

http://www.mangago.me/read-manga/uzumaki/
And I've heard other works by this mangaka, Itou Junji, are just as terrifying
http://www.mangago.me/read-manga/20th_century_boys/ What sends chills down my spine are usually psychological thrillers. This manga's chalk full of inexplicable disappearances, creepy vibes (the kind you get when something monstrous comes lurking in a peaceful setting), dark conspiracies underfoot, and an enigmatic villain to top it all off. Although it's not horror, I believe the affect is the same, and it'll have anybody biting they're nails. Takes awhile to build up to it though.

Thx you guys, I will check them out!!