Horror
http://www.mangago.me/read-manga/mononobe_koshoten_kaikitan/
http://www.mangago.me/read-manga/kami_no_hidarite_akuma_no_migite/
http://www.mangago.me/read-manga/timing/
http://www.mangago.me/read-manga/preta/
http://www.mangago.me/read-manga/the_surviving/
http://www.mangago.me/read-manga/ikki/
http://www.mangago.me/read-manga/killing_morph/
http://www.mangago.me/read-manga/kouya_ni_kemono_doukokusu/
http://www.mangago.me/read-manga/shen_ze/
http://www.mangago.me/read-manga/promised_orchid/
http://www.mangago.me/read-manga/300_beats_per_second/
http://www.mangago.me/read-manga/pet_shop_of_horrors/
http://www.mangago.me/read-manga/gift_plus_minus/
http://www.mangago.me/read-manga/kurosagi_shitai_takuhaibin/
http://www.mangago.me/read-manga/noah_of_the_blood_sea/
http://www.mangago.me/read-manga/diner/
http://www.mangago.me/read-manga/shiga_hime/
http://www.mangago.me/read-manga/the_girl_who_sees/
http://www.mangago.me/read-manga/yamiyo_ni_asobuna_kodomo_tachi/
http://www.mangago.me/read-manga/you_will_hear_the_voice_of_the_dead/
http://www.mangago.me/read-manga/franken_fran/
http://www.mangago.me/read-manga/angel_of_slaughter/?K4QF
http://www.mangago.me/read-manga/wakusei_closet/
http://www.mangago.me/read-manga/suicide_girl/
http://www.mangago.me/read-manga/dai_dark/
http://www.mangago.me/read-manga/xxxholic/
Mystery
http://www.mangago.me/read-manga/yuureitou/
http://www.mangago.me/read-manga/monster/
http://www.mangago.me/read-manga/boku_dake_ga_inai_machi/
http://www.mangago.me/read-manga/the_planet_walks_alone/
http://www.mangago.me/read-manga/zankyou/
http://www.mangago.me/read-manga/shinrei_tantei_yakumo/
http://www.mangago.me/read-manga/koroshi_ai/
http://www.mangago.me/read-manga/moritat/
http://www.mangago.me/read-manga/love_in_murder/
http://www.mangago.me/read-manga/american_ghost_jack/
http://www.mangago.me/read-manga/yuukoku_no_moriarty/
http://www.mangago.me/read-manga/brutal_satsujin_kansatsukan_no_kokuhaku/
http://www.mangago.me/read-manga/from_the_red_fog/
Theses ones are some of my personal favorites
Any horror or mystery mangas... ? (=・ω・=)