- Grimgar
- Mushoku Tensei
- Hunter x Hunter (2011)
- Frieren
- Fullmetal Alchemist Brotherhood
- Dorohedoro
- Dungeon Meshi
- Made in Abyss
- Ascendance of a Bookworm
- One Piece
From the most recent discussion about the best anime worldbuiiding, my choices continue to be Made in Abyss—as in I agree with the article in this case—and Violet Evergarden, but Witch Hat Atelier is getting to be a contender.
Grimgar is quite an intersting choice—older, obscure, downbeat single-cours isekai. Maybe the listmaker read the LNs?
I’d add The Twelve Kingdoms, and possibly The Slayers and Kyo Kara Maoh! to this (there’s plenty in both to explore, but both sometimes drop something silly for purely comedic purposes, like the vegetarian sharks).
I’d say The Twelve Kingdoms blows basically everything else on this list out of the water in terms of world building.