The only books on photography that I've ever read are all written by John Hedgecoe, the man who is said to have taught the World to photograph. As I have not read any photography books by other authors, means I can not compare and explain why would John Hedgecoe's books be better than others. But his name was not yet mentioned in previous answers, and I think it should have.
John Hedgecoe has written more than 30 books on photography, which have sold over 30 billion copies and been published in 37 languages. so there's plenty to choose from. I learned a lot from his earliest books, especially from Manual of Photography (1977). Unfortunately this book is not available today, and even if it was, it might not fully satisfy digital photographers anyway. But he authored new books constantly, covering digital photography too in several of his books, for example in New Manual of Photography.