Flowers for Algernon - classic sci-fi that holds up well.
Originally published as a Hugo Award winning short story in 1958, and later published in a longer form as a Nebula Award winning book in 1966, Flowers for Algernon is considered classic Sci-Fi at this point. It is a story about Charly Gordon, who has an IQ of 70, and the impact of potentially life-altering surgery that hopes to increase his intelligence. Charly's life is limited, but happy, prior to the surgery, and this book explores the ethical and moral dilemmas that come along with changing someone's life for the "better." In this case intellect comes at the cost of happiness, and this book explores the impact of the change on Charly's relationships and his own mental well being.
I feel like the story holds up well, although it is now considered to be a bit controversial because of the way in which it depicts the mentally disabled. Being a product of its time it doesn't seem controversial to me at all. Interestingly enough, all of the characters in the book are based on real people from the author's life and even the idea for the story comes from some of his actual experiences. The book was turned into a movie in 1968 (Charly) and the actor who played Charly Gordon won the Academy Award for Best Actor with his performance.
I often hesitate to revisit the classics for fear of ruining my impression of them, but in this case I am glad I did. I chose to listen to the audiobook version of this and Jeff Woodman does an excellent job as the narrator. He handles playing the role of Charly very well and he is able to properly convey the changes in Charly's intellect with his performance. If you haven't read this one in a while, or have never read it, I would definitely recommend you pick it up in one form or another.