For me the most overrated book is My 60 memorable games by Fischer.
Many experts consider one of the best chess books of all time.
Honestly, I read the first 4 or 5 games, I recognize that it is a good book, but Fischer puts few comments, it seems a little didactic book.
I think the books of games Alekhine, Botvinnik, Keres, Kasparov, Tal Bronstein are better for me. His comments are more extensive and didactical.
I think most chess players would agree that there are some definite "classics" when it comes to chess literature which are held in extremely high regard by most of the chess comunity. Books like "Art of Attack in Chess", "My System" and even more modern ones like "How to Reassess your Chess." I'm interested in hearing about books - not necessarily classics - that didn't at all meet your expectations, particularly if they are in general very highly rated by most other chess players.
I'll start off with what I imagine will be a controversial example: "The Life and Games of Mikhail Tal". I seem to be the only person on the internet who thinks this. It has some good games - particularly extracts or games that aren't fully annotated - but not enough to convince me that the book or the player is deserving of the near universal praise that they both receive.