Which are the milestones of fantasy that fantasy reader should definitely read?

throughout years I read C. S. Lewis, Rick Riordan, Cassandra Clare, Sarah J Maas, J. K. Rowling, Christopher Paolini and Leigh Bardugo. I experienced that despite my love for shadowhunters world I love high fantasy, so which are the most monumental and important authors of the genre? Should I read Tolkien and then?