At its core, Re:Zero is a love story. It follows our protagonist, Subaru, as he tries to win the heart of Emilia, a prospective queen well out of his league. To be honest, the show was a bit of a chore at first. Subaru doesn't start off a very likable hero, and it was not easy to pull for him. He was selfish, arrogant, and somewhat obnoxious. It seemed like the first half of the series was trying to layout the foundation for just how flawed he was. As rough as it was to get through this setup, though, Re:Zero would have only been half as good without it. In my opinion, its real strength is in how brilliantly it celebrates the human capacity for change. I can't help believing the creators deliberately made our hero such an unbearable character to show us that anyone is redeemable (albeit through some extraordinary circumstances). I found myself very much on Subaru’s team by the end, which surprised me. Perhaps I'm too much of a romantic, who knew :)?
I highly recommend Re: Zero to anyone and everyone. I can't say it's title as number 1 is justified, but it is certainly worthy of praise. Do be patient with it, though, and let us know if you saw in it the same things I did!