I'm in! Thanks for the giveaway, Azilut! +1
Speaking of anime, I would recommend Higurashi When They Cry(wiki link)
and its sequel, Higurashi no Naku Koro ni Kai(it was never dubbed in English).
I was recently told about the series as being a mystery anime with moments of extreme violence and horror. At this point I wasn't all that impressed, though the fact that, apparently, there are no cheap scares such as jump scares due to loud noises, did appeal to me. However what convinced me that I should watch it is this: SMALL SPOILER
the action takes place in a time loop. The scene is set up, with hints to the mystery being revealed, and then a violent murder takes place and the time loops back to the beginning. Nobody is aware of the time loop, but the actions of the characters from past loops affect the current loop, which changes the story and allows the mystery to be slowly resolved.
I realize that CthuluIsSpy
already mentioned Higurashi, but the point of the giveaway was to convince you as to why you should watch the media we're recommending. Plus, a little backstabbing is appropriate for the season. :P