This is a really fascinating discussion, and I couldn't help but add my opinion. First, you should know that Tolkein really was a Christian, a Catholic to be precise, and what's more he was instrumental in Lewis' salvation. I think I can find a link for that story.... Or here's a quote:
1931
( 28 Sept) Lewis became a Christian: One evening in September, Lewis had a long talk on Christianity with J.R.R. Tolkien (a devout Roman Catholic) and Hugo Dyson. That evening's discussion was important in bringing about the following day's event that Lewis recorded in Surprised by Joy: "When we [Warnie and Jack] set out [by motorcycle to the Whipsnade Zoo] I did not believe that Jesus Christ was the Son of God, and when we reached the zoo I did."
As for "Rings" being in the Bible bookstore.. well I don't mind the books being there myself, as Tolkein was a Christian, but I don't like the idea of it being a massive display, toys and all, because the series isn't really a "Christian" series. My local BBS does carry the books, but they aren't a big deal. It also carries many other books by Christian authors that aren't necessarily "Christian books" if that makes sense.
And Narnia? Well first it's
not an allegory! The stories are somewhat allegorical, yes, but they are meant to reflect Biblical truths, not represent them. An allegory is something with a 1 to 1 comparison, like Pilgrim's Progress. A great part of Narnia is not allegorical at all. But the Biblical truths in the books are beautiful. I remember when I was little reading The Lion, The Witch, and The Wardrobe for the first time and excitedly telling my mother all the Biblical parallels.
And Harry? Well.... I've never read the books, so I've decided to have no opinion. I've chosen not to read them or watch them because
A) I am concerned that they may be a little too "witch-crafty" and
B) They don't interest me... they seem a bit poorly written, eh?