Personally, I'm watching:
Grand Blue: Didn't expect much from the adaptation, but it's pretty decent. We shall see if the anime manages to make the show justice, since it's one of the funniest manga ever.
Overlord III: More Overlord.
Hataraku Saibou (Cells at Work): Probably the anime of the season. Everyone's already in love with it, and it's indeed pretty good. A doctor even made a thread on Reddit talking about the first episode.
Chio-chan no Tsuugakuro: Another surprise! I expected it to be quite dumber, but the show's actually quite entertaining.
All hail the Platelets, which the show actually has scientific reason to make lolis and shotas, due to how small they are.