Hellsing. Kuroshitsuji. Elfen Lied? Higurashi.
Ah there was one i read about two people trying to find out who the murder living in a maze under a clock tower is
The mystery behind the whole thing is great and is the only thing that kept me going even though i was terrified lol
Its called yuureitou
Lots of gore and death if i remember correctly
Theres also the manga called doubt
Never finished these because im a wimp haha
the "parasyte" one that's been on the recommend list lately is pretty good. A bit bloody, but the plot is excellent.
http://www.mangago.me/read-manga/deadman_wonderland/
http://www.mangago.me/read-manga/mahou_shoujo_of_the_end/
http://www.mangago.me/read-manga/battle_royale/
http://www.mangago.me/read-manga/mirai_nikki/ (Not really horror, but more thriller like.)
http://www.mangago.me/read-manga/ghost_hunt/ (More lighter.. in a way.)
Are there any good horror mangas? Mangas that have a very interesting and enticing plot, but do include horror and gore?