Maybe it's not among your 50 favorites, but it's probably the most significant, in that it got the most people interested in fantasy, and is even now the most well-known fantasy series.

If I were doing a list of external significance, definitely I'd put The Lord of the Rings on there. I just know that it wasn't one of the books that got me into fantasy: I was already in high school by the time I discovered it.

I've read 5 books off your list, as compared to 4 from the original list.

Which five and which four?

I have no appreciation for the classics.

Hey, you introduced me to The Sandman . . .