This was so much fun, my gosh. As Neil Gaiman explains in the preface, it's somewhere between the original book and the final cut of the show, so it provides some insight into the adaptation process (from new scenes that don't appear in either the original book or show, to familiar scenes that appear in both). The stage directions are hilarious, and I loved getting a sort of behind-the-scenes look at the creators' intention between certain lines, camera angles, etc.

(Having reread Good Omens immediately prior to this, and having rewatched the show several times, I didn't get quite as much enjoyment out of this as I think I could've otherwise — but still, it was fantastic.)