I've really started to build up my library as of late and there is so much out there that you just have to focus on what you like. For instance, there are "how to/care" type books, non-fiction accounts from herptologists, gossip/drama type herp books, and even old timer snake hunting books. So it really just depends on which direction you want to go. I like them all with the "how to/care" type books being my least favorite. Now there are exceptions to the rule, for example the Barker book that you mentioned is excellent. My only complaint with it is that it's physically large!
A few of my favorites:
"You belong in a Zoo"
"Lizard King"
"Stolen World"
"The Keeper and the Kept"
"Tales of Giant Snakes"
"The Complete Series" Boas, Chondros, BP's, and now a new Carpet book.
"Cobras in his garden" (Bill Haast biography)
"Gone Snake Hunting"
"The Snake Charmer" - sad
"Keeping and Breeding Australian pythons"
"Pythons of Australia"
"Snakebite survivors club"
"Snakebit" (mentioned above)
"Big Snake" - funny!
If anyone reading this has a copy of "Pythons of the World - Vol 1" for sale, please PM me!