Bungou Stray Dogs
Sket Dance
Naruto (everybody knows how superb it is) :
Ghost Hunt (horror)
When Seagulls Cry (horror, gore, psychological)
Gakkou Gurashi (horror, zombie, drama)
A Corpse is Burried Under Sakurako-san's Feet (similar with Detective Conan)
Comet Lucifer (sci-fi meets fantasy)
Owari no Seraph (if you are fond of shounen ai and vampires)
Betrayal Knows my Name (shounen ai, reincarnation, drama, vampire)
Photokano (ecchi)