A few quotes I found especially interesting or funny from authors about Middle-earth/Tolkien:
“Tolkien was the first to create a fully realized secondary universe, an entire world with its own geography and histories and legends, wholly unconnected to our own.” -George R.R. Martin
“Frodo travels through Middle-earth like some kind of God-sent integrity test. The Wise, if they were truly so, upon seeing that he had come to visit, would shriek, ‘Oh, no! It’s that fucking hobbit! I’m not in!’ and slam the door in his face.” -Michael Swanwick
“The Lord of the Rings [. . .] led me to realize that a good fantasy is one that springs from a fully realized world, and that constructing that world can be an awful lot of fun.” -Esther Friesner
“Do I still think, as I did then, that Tolkien was the greatest writer in the world? In the strict sense, no. You can think that at thirteen. If you still think it at fifty-three, something has gone wrong with your life.” -Terry Pratchett
“Tolkien described Gandalf as having ‘long bushy eyebrows that stuck out further than the brim of his hat.’ If you read that, it’s one thing; but try to paint it and it looks as goofy as hell.
You wouldn’t even do that in a cartoon.” -Greg & Tim Hildebrandt