In my opinion, these are all wondrously well made, enjoyable, gripping, and/or meaningful. (Or in Marimite 3rd's case, just so wonderful!)
Note that Higurashi Kai and Tale of Melodies are sequels, obviously you'd have to watch the earlier seasons, but in both cases the earlier seasons are excellent as well.
This list is somewhat ordered. ~(1, 22, 33, 4444).