I see everyone is posting fiction books here, but since you did not specify I would recommend a great book that I read many years ago called "Lost Gold & Buried Treasure: A Treasure Hunter's Guide to 250 Fortunes Waiting To Be Found." It was written by Keven D. Randle, who was a Captain of the US Air Force Reserve. As far as I know, nobody has managed to find any of the fortunes in the book since it was written, but it still makes for a very interesting read. It actually amazes me how much lost treasure there are still left in the world, just waiting to be found.

A more recent example would be the W.C. Jameson book, Lost Treasures & American History. The author is actually a professional treasure hunter and has first-hand experience with searching for all the buried treasures and lost mines that he describes in the book. From lost Spanish gold in the Sandia mountains to the Benedict Arnold Treasure and the treasure of Sir Francis Drake, there's plenty of good stories in here.

My final choice would be The book of Buried Treasure: Being a True History of the Gold, Jewels, and Plate of Pirates, Galleons, Etc., Which Are Sought for to This Day by Ralph Delahaye Paine. This book is in the public domain I believe and while it is quite old, it contains more than enough great information about lost or buried treasure to keep you turning the pages. Just don't be surprised if you get the urge to invest in a metal detector and go out looking for your own buried treasure after reading all these books.

A lot of people have mentioned it already, but it really is the classic books that only become better with age and upon re-reading. That is one of the reasons why I keep returning to this site as I can easily get all those half remembered and semi forgotten classics to read again on my phone. Sometimes some of the books are as bad or boring as I remember from my days being forced to read them at school, but most of the time a book turns out to be even better than what I remembered or so much better than what I thought. What I have also found is that while it shouldn't really matter, the look of a book can also shape my opinion. Many classic books are like these dusty, moldy looking things when you find them a secondhand bookshop, but if you see them digitally with a new cover they almost look more appealing. This is just a personal observation of course and your mileage may vary.

This is a very tricky question to answer because it would depend on what your definition of a plot hole is. The traditional belief is that a plot hole is something in the story that either allows for illogical things to occur or where things happen that contradicts what has already happened before. The problem with a lot of books is that authors try to be too clever and end up writing themselves into a corner. The only way out of it is to then come up with something far-fetched and illogical to resolve their conundrum. This is very disappointing for readers as they read in suspense, expecting to find out how the impossible is going to happen, only to find out that the author didn't know either and just faked it. You can think of it as the literary equivalent of those television shows that end in a cliffhanger of the hero being in a building that explodes, only to walk out at the start of the next episode looking only a little dirty. It insults the intelligence of readers and has spoiled many a good book as well. If only some authors would put a little more thought into their overall stories this wouldn't happen so much, but the problem is that a lot of authors write books in a series these days instead of stand-alone novels, which makes it way harder to keep track of all the loose threads. A good example of the latter would be A Song of Ice and Fire. Now before anyone starts attacking me, I love the books to death, but anyone who has read them will know that they are full of glaring inconsistencies. I'm not going to go into any specifics for the sake of those who have not yet read the books or watched the show, but suffice to say that they are there for all to see. The Harry Potter series is another good example, although it is quite amusing to see some of the fan theories that have popped up over the years to try and justify them!

Yes, I read The Salmon of Doubt: Hitchhiking the Galaxy One Last Time because it features the work of Douglas Adams. Most of this book is just a collection of essays and other unpublished material by the author, but it also has the incomplete novel, "The Salmon of Doubt" in it. It's an interesting albeit sad read if you are a fan of Douglas Adams and it is clear that the author still had a lot of work left to do on it. It is said that Adams wasn't happy with the story and wanted to shift it so that instead of it being a Dirk Gently book, it would be the conclusion to the Hitchhiker's Guide to the Galaxy series. If you are not a fan of Douglas Adams then there's nothing for you in this book, but for everyone who eagerly waited for everything he ever released, it's a fitting farewell to an incredibly talented writer.

My personal taste runs more towards horror, so these books might not be what you are looking for, but they do use Hollywood or the film industry as a backdrop.

Clive Barker - Coldheart Canyon ~ This one is about a movie star who thinks that plastic surgery is the answer to getting himself back in the limelight. As is often the case, the operation is botched, and the actor ends up with a disfigured face. To stay out of the public eye while recovering, the actor moves to a secluded area just outside of Hollywood called Coldheart Canyon. This novel is by horror maestro Clive Barker, and its description as a Hollywood ghost story is very apt.