It hurts to give this a 4/5 because I adored the first half so much but the Neverending Story has a much weaker second half. It's essentially two books, with the first a strong 5 star novel and the second a 3 o 3.5.
Atreyu is just a much nicer and more engaging protagonist to read about than Bastian. There's also a great framing device used in the first half, with Bastian reading the book and Atreyu sometimes hearing him react to what's happening.

While I enjoyed the second part of the book, it becomes much less focused and is really like watching a 25 episode tv show with a monster of the week and the vaguest of season plots.
There's also a line used so many times to wrap up b-plots without resolution that I wanted another two of three books '...but that's a story for another time'. It's said so much that it went from charming and tongue in cheek to feeling scammed that seemingly no side characters get a fully resolved plot.
The Neverending story is a wonderful book really, and I'm only sour there isn't more of the world itself, without Bastian and his human-ness getting in the way.

I propose that the Jim Hensen company are given all the money to create a series similar to their Dark Crystal series, set in Fantastica.