In case you missed my ninja-edit
If you want gory stuff with PLOT, like real plot (not the ones typically found hidden in bikinis or sweaters or school uniforms) you probably want to try Shiki.
It has vampires, blood, and lots of guro bits much like Higurashi, the best thing is the constant but fair delivery of actual creepiness stemming from the fear of the unknown perpetrator of the crimes in that secluded village. While Mirai Nikki succeeds with bringing the battle royale front of yandere killing goodness (and even an end to be reckoned with) Shiki has its own very unique content of mystery with a kind of forebodding doom the first episode you lay eyes on it. The brilliance behind this underrated show is a box of goodies for those who try it.
If you are willing to last through it, Railgun actually offers something oddly familiar to the series of Index. Index is... well, Index, the series completely neglects the character it bases its name on nor does it bother to give that rut a role other than eating and sleeping and being generally useless in the actual battle. Hence, watching Railgun is fantastic. Nonetheless, unless you pick up both seasons of Index and Railgun in between the story would make a lot less... 'sense' to you.
Still I guess you can consider.
Are you high on the want for a love story that isn't afraid to cross borders?
like the borders of 18++ and above? Yosuga no Sora offers something quite unlike your typical harem show, it comes in 4 small parts (5 if you count the extras) where the MC (being DENSE as usual) finds love among 4 different girls. If you watch them in order of 1-12 it would make one complete story, but if you watch it in random it becomes another story of a sort, highlight of this show is brocon and siscon and incestual relationship in a little known backwater village... so it is kind of... disturbing in a way, but somehow, it feels natural as well to expect it.
One thing I never finished as yet, a reverse watching anime (24 - 1st episode) called Touka Gettan, I dunno why I haven't really finished it, but it has one of the best art for something based off a visual novel (which we used to know as H GAME). It has time travel beauties fighting to save what I believe was a God forged weapon designed to kill deities and demons and stuff like that... it is quite epic, consider the cast is made of solid top listed seiyuus.
