One Piece is just… built different when it comes to worldbuilding.

From this list HunterxHunter, but I think Naruto

HxH. From what I’ve seen of one piece the world building was good but HxH’s is better. Mind you I haven’t seen all of one piece.

I think, of the anime I’ve seen, the best are Fullmetal Alchemist Brotherhood and Last Exile. Both of those do a good job of focusing in on one place or ship in the world while still fleshing out what lies beyond.

Hunter x Hunter

I'll go with Hunter x Hunter. I haven't watched One Piece yet.

Toriko had big potential but didn't deliver that

Tho it is hard second after one piece

Never watched one piece but i already know its the best

But id have to go with aot...

Wow no one is sayin toriko even though it has incredible world building lol

Straight up One Piece. Nothing compares to the level of World Building One Piece has done.

Black Clover, Fairy Tail and HxH have great world building but they're still not comparable to One Piece.