I missed this when it was published a year ago, but in a list of File 770's best articles of the last year I found Cat Eldridge surveying a bunch of authors on the question, "What's Your Favorite Tolkien?"
Most of them picked either The Hobbit or The Lord of the Rings, indeed some hadn't read anything else by him, and a few who picked one of those two didn't like the other. A few went for the tale of Beren and Lúthien or The Children of Húrin.
The respondent who's closest to my own views is Elizabeth Hand, who picked The Lord of the Rings because "it imprinted on me at such an early age ... it was still a cult novel, and you had a real sense that you were in some secret, marvelous group of insiders who had visited a place not everyone knew about." Sort of, for me: I'm Hand's age and also imprinted on it from an early age in the 1960's. But I didn't feel part of a group of insiders; I felt terribly alone and clutched the book by myself. From my first reading at eleven, I never found anybody else who'd read Tolkien's work and wanted to talk about it until I was seventeen.* Six years, with no expectation that the durance will end, is a long time when you're that young. As a result, when I did finally find the Tolkien fans - remember that this was long before the public internet - I wanted never to leave, and I never have. Half of what makes up my life has been built around this.
As a result of that intense interest, I have, like Hand, been drawn to Tolkien's other works. She particularly notes the "History of Middle-earth" series, and says "I'm continually so amazed by what this one man came up with, the intensity and single mindedness of his obsession. And I get sucked into it all over again." And that is quite close to what I feel. Not the intensity so much as the sheer boundless creativity of one mind, its ability to deploy the illusion of reality so profoundly.
But one reason to focus on The Lord of the Rings is that it's so large. It'd probably be my choice of desert island book. But word for word, because it's quite short, my favorite Tolkien is something that nobody on the list mentioned: Smith of Wootton Major. I once wrote an article explaining why I thought it was a perfect fairy-story: partly because of what the author chose to leave out.
*I identified with a line about Gollum in The Hobbit (my introduction to Tolkien, and also a favorite): he "always spoke to himself through never having anyone else to speak to." That sums up my childhood relation to peers in a nutshell.
