In the Woods: great literature or utterly disappointing?

I recently read In the Woods by Tana French. It was suggested during book club by a local author. I went online and read a sample chapter and was very excited at the prospect of reading this book. For the next 2 1/2 days I worked my way through the 438 (or so) paged book and came away disappointed. The beginning was fantastic, a murder of a young teenager in a small town in Ireland, two detectives who are called to the scene, and one of the them hiding a secret from his childhood that took place in the same town.



I fell in love with the characters and got swept up in the plot. All of a sudden, with 150 pages to go, I just wanted it to end. I wanted the story to wrap up -- needed to know who the murderer was and how it connected to the detective's past. So I soldiered on through the last 150 pages and came away with one mystery solved and one unresolved.



I never thought of myself as a person who needed closure or everything wrapped up in a bow at the end. Yet, I was frustrated by the fact that one of the mysteries would never be solved and that made me dislike the book overall. So here is the question: Have ever read a book (or seen a movie) that you completely loved until the ending? If so, what was it?