Everything about his Fantasy works, to me, is just perfect. His worlds are so detailed it's hard to believe they never existed. Of course, the plot/characters of LotR are a bit cliche, but as Tolkien was the grandfather of modern Fantasy, that doesn't really count in his case. And it's all executed so beautifully I don't find myself worrying. After all, not everything ends happily (after I finished the trilogy and then read Arwen's Story, I was left feeling moved but at the same time there was a sort of sadness and longing for a world like Tolkien's. These feelings are even stronger when one finishes The Silmarillion).
And his languages are awesome! They inspired me to study Finnish.
