Yeah.. Isekai is not the best anime genre there is due to extremely high chances of harem and repetitive plot, however when it's done well it really shines.
Like overlord for example, not only it has a pretty good worldbuilding, also lacks of harem and has pretty good male characters' designs like ainz's alter ego: momon (his armor is amazing) , gazef stronoff and my fav, sebas tian.
Tensura is also pretty nice... I mean, If you don't mind some fanservice, of course. There are some orcs (not the wow kind) , ogres, dwarves and a really cute guild master.