I like Tolkien's work, but like anything popular in pop-culture; there are differing views on "what it is". I usually ask "So, what do you think of Tom Bombadil", the answer tells me a lot about what Tolkien's work is too someone else.
I've got a few sure-fire questions like that.
Oh! Ya Glorantha is awesome. What's your opinion on Ducks? Do you like Dark Souls 2? Did you ever get to play Dungeons & Dragons Fourth Edition?