Definitely Re:Zero.
Plus, the same studio that animated Steins;Gate is animating this - how can I miss it?
Kabaneri is my second choice though, it's pretty good, and honestly speaking, I would probably nominate it for AoTS, if I remove my bias for Re:Zero.
Others are kind of shitty imho, I enjoyed Big Order for the first few episodes because of how purely weird it was (especially the instant-pregnancy... wtf!) but it's dropped off since episode 4.
Then again, good first impressions and leaving with a bad taste in my mouth is what happened with Mirai Nikki too, when I watched that, and this is a work by the same author, so...