I think I have far more books than I should!
I enjoy anecdotal books. I like hearing the stories behind the images. Phillipe Halsmann's "Sight & Insight" is my favourite. Brian Griffin's "Black Country Da Da" a close second (I have a signed copy!).
For just picture books Elliot Erwitt's "Personal Best" and "Found Not Lost" for my favourite Street Photography, Jane Bown's "A Lifetime of Looking" and Andy Gotts' "Degrees" for portraits. For other work that's difficult to categorise, Diane Arbus' "An Aperture Monograph" and Fay Godwin/Toulson's "The Drovers Roads of Wales" are up there. I also really enjoyed Gavin Watson's "Skins & Punks" documenting his youth in High Wycombe which was where I grew up. So much good stuff out there.
Bruce Barnbaum's "The Art of Photography" and Ansel Adams' trilogy (The Camera, The Negative and The Print) are the best of the "instruction" books I've come across.
I'd heartily recommend Clive Limpkin's "The Battle of Bogside" telling the story of his reporting of the troubles in Northern Ireland. Scary stuff being a war photographer, especially in that war.
Edit: The Limpkin book is at silly prices on Amazon. You can get it direct from the publisher for a very reasonable price:
https://ghpress.com/shop/product/battle-of-bogside/