Honestly I didn't go into it with many expectations. The only isekai I watched before Re:Zero was No Game No Life (I guess SAO when I was much younger if you want to count that...), since I only watched so few I didn't know the genre trends. Even after Re:Zero the only other one I've watched was Konosuba, so I really don't know much about the genre other than its basic premise.

Sure the story hooked me, but what really surprised me was the double length episodes (I watched Directors cut without knowing it at first). I've watched shows like AoT, Akame ga kill, and Psycho pass, so the intense psychological thriller aspect of the show was kinda up my alley from the start. Also it reminded me of Hunter x Hunter in some ways. They both feel like realistic, logical worlds with complicated politics, complex magic, and characters that are extremely natural. What I mean by natural is they only appear in the narrative if it makes sense for them to be there. This might seem like a small detail or insignificant but I really think having logical decisions from characters outside of the narrative, in such a way that Tappei noticably records their actions in notes beyond the narrative we see (I'd be genuinely shocked if he didn't track what the other candidates are up to during arc 4 for example), it feels incredibly realistic to me. That's one of the big reasons Hunter x Hunter is my favorite anime right now, and Re:Zero is the only other anime I've watched with characters written like that. It's a major reason why Re:Zero is the only show I can think of that might surpass Hunter x Hunter in my mind. If they do arc 6 justice, it might be enough, I'll have to wait and see though.

I think it's funny saying all this because I almost dropped the show on my first watch. I binged up to episode 17 last spring, and stopped for unrelated reasons for a couple of days. When I had time for anime again I decided to watch something else because I felt Subaru was looping too much. I was 20 minutes from changing my mind. I'm happy I picked it back up right when S2 cour 1 ended, because it got me into the Web Novels too. It's one my favorite fantasy worlds and I almost missed it by accident.