They cover a lot of different territory. Maybe 20% of the essays between the two giant books are same. The Goddess book is all fiction, so it’s pretty distinct from the other two. I’d recommend the goddess book if you’re getting someone a gift.
Between the two 800-pagers, the Library of Scott Alexandria was written in 2014, so it’s more classic Scott, and more focused on rationality specifically. I would personally prefer the newer SSC Abridged.
Thank you for your kind words :)