Recently read the convergence trilogy and one of the main characters is trans. I liked the books.

Additionally the left hand of darkness is about a planet full of genderless people that change to male/female idk if that is considered trans. The book in general is commentary on gender norms in our society. This one I think puts the most emphasis on gender of the three.

And finally one of the main characters in Robin Hobb's Realm of the elderlings series is also trans or non-binary I think. It is a great depiction of how the actions of a person are more important than their gender, but it is not the main point of the series. Still a great fantasy series I think.

P. S. Everything from Le Guin is great and I highly recommend it.