Early one morning last week, a Christianity Today International executive joined thousands of other Americans by driving out to a major retail chain to snag a newly advertised $15 copy of the The Lord of the Rings: The Two Towers DVD. He arrived to find the bins already cleaned out.

Had he then headed to his local bookstore, our colleague would likely have found a similarly brisk trade in Tolkien's trilogy itself. Not that those books needed Peter Jackson's help: They long ago entered the rarified ranks of the blockbuster bestsellers.

But the millions of DVDs and books sold represent only the "camel's nose" of Tolkien's influence under the tent of popular culture. Because that brilliant, devoutly Catholic Oxford don created not only a phenomenon, but an entire genre. Little did he know, as he sat with C.S. Lewis in the latter's Magdalen College rooms in 1936 and determined to write "the sort of books they liked to read,"that within a half-century, entire bookstore shelves would groan under the offerings of his admiring imitators.

In Christian History's new special issue dedicated to Tolkien, author Aaron Belz provides a handy guide for readers who want to sift the wheat from the chaff in this abundant harvest of "Tolkien-esque" fantasy novels. Here is his survey of the best of these novels—divided into children's books and books for older readers:

When The Lord of the Rings was published in 1954-55, nothing like it had ever been seen. This epic tale in its elaborately devised world sent shock waves through the publishing world. It was, in the words of Tolkien biographer Tom Shippey, "a one-item category." But soon, it was clear that the category was destined to overflow. J.R.R. Tolkien had done nothing less than found a ...