i've seen people talk big about a lot of isekai animes and tbh they usually don't hit (because re:zero isn't there ofc). MY top 3 isekai are re:zero at first ofc, dont hate me but mushoku tensei at a close 2nd and konosuba/sao because i can't decide which is better. i bet you're asking why tensura or smth isn't on here. i'll say this once and i'll say it again, tensura is mid and overrated. the concept is pretty bland itself and its not that enjoyable. i know i've only watched the show and maybe it gets better in the manga or LN but i can assure you the animes that i've listed are at least 3x better than tensura. for example, re:zero, the perfect isekai anime, cool story about a loser teenager who gets transported to a magic world and finds himself able to return by death whilst trying to save a young girl. there's more to the story but i'll save it. the story and character writing is what makes a good anime (especially isekai's since getting transported to a world is kind of boring and repetitive). i rest my case.