Just to add to this, since
Ruin Explorers, Lodoss War, Slayers and
Berserk have already been listed, but there's actually a non-isekai fantasy anime slotted for next month's release. I don't know if it's already been mentioned on the thread, but it's called
Frieren: Beyond Journey.
I normally don't recommend modern titles, but this one looks interesting in that it'll probe the "Deedlit Dilemma". That is to say, it'll delve into the harsh reality of being the lone elf character in a group of fantasy companions, and what it'll be like for that character to watch her companions perish as she lives forever.