I loved Never Let Me Go by Kazuo Ishiguro. The writing style was great, I hardly wanted to put it down! The relationships between the characters reminded me so much of my early childhood friendships. I liked that the reveal was not only slow, but that the reader already expects what is coming because of the little clues woven throughout the story. This might be a slight spoiler, but

Spoiler

I found it really refreshing to read a dystopian novel that doesn't end in a revolt.

I am also a strong believer that not all books need a happy ending. So if you need a book to end on a good note I should warn you this one ends bitter-sweetly.