One fascinating aspect of Tolkien’s oeuvre is that his writings are, how to put it, endlessly derivative. Not only did he use words from different languages, motifs from different mythologies, and images from different poetical traditions. He also mercilessly raided the writings of George MacDonald for characters and plot elements (try reading ‘Phantastes’ or ‘The Princess and the Goblin’ to appreciate just how freak…
He did it so well that most "high" fantasy that came out after him felt derivative of Tolkien. I'd really like to see counter-examples though; I feel like I haven't dived into the genre enough, in part because I'm turned off by the sheer volume of some book (series) on the one hand, and the juvenile tropes (generic hero's journey formula) on the other.
UKLG's Earthsea is the series that I hear most often loved by other authors, although I'm not familiar with it myself.
Then there is Pratchett, who set out to do simple parody of high fantasy and ended up creating a deeply humanist character-driven universe.