I'm pretty sure you've seen most of them, they might not be masterpieces but far above the trash (like Smartphone Isekai) you are refering to in your first post.
Let me list some for you and let me start with one you might not have watched yet.
Castlevania - the english dub is very good. Mutliple seasons full of goodness.
And now let me list some you probably know already but that were also pretty/very good. Fantasy/Historic/Semi-real/Isekai settings in random order and random genre mix:
Vinland Saga
Goblin Slayer
Spice and Wolf
Berserk
Fullmetal Alchemist
The Heroic Legend of Arslan
Attack on Titan
Maoyuu Mao Yuusha
Magi: The Labyrinth of Magic
Grimgar of Fantasy and Ash
Record of Gancrest War (still has the best fire-mage character there ever was in anime imho, at least as long as I consider Sypha from Castlevania as an Elementarist)
Maria the Virgin Witch
Rage of Bahamut
I'm leaving out the really old ones because honestly, I can't watch them anymore, anime just doesn't age well... or at least most of the artstyles didn't.
Slayers used to be funny_af though (the english dub more so than the japanese one)