17. Funny read...Good Omens by Terry Pratchett and Neil Gaiman
I started this in college and couldn't get into it, I tried again more recently and I love it. It has demons, angels, the Apocalypse and the Anti-Christ but in a fun way! It was a collaborative book between authors at a time when to send drafts to each other they had to send floppy discs through the post to each other.