Higurashi no Naku Koro ni Kai, Shinsekai yori Recommendations
In Higurashi, I was like " who's the next killer?" or "I wonder who's next to die heuheuehue" . But in Kai, I started to like the characters and cheer for them wishing to not be hurt or not to die again which is I why I chose the 2nd season of Higurashi in this recommendation. The same goes for Shinsekai Yori, at first you don't about the people in the story but they'll eventually grow on you, atleast that's the case for me. Both anime have great suspence, amazing developments, and mind puzzling stories.
There are a lot of questions which are unanswered to the protagonists of these 2 series as well as to the viewers, when the answers are revealed it brings shock not only to the protagonists but also to the viewers as well.