This is a question that thankfully arises frequently, particularly when I am asked or ask for recommendations. A question that I suppose is as unanswerable as "What is Art?"
At a precocious age I took it upon myself to read the great classics. The canon of (mostly English) literature, followed by the best of world literature. In hindsight, I would have to agree with Churchill that some books are read too young. Some require life experience to be understood, others remain as unrelatable then as they are now and many hold up to a reread years later. I loved The Fountainhead, Moby Dick, Huck Finn, Notes from the Underground, To Kill a Mockingbird, 100 Years of Solitude and 1984. They are among the great books that were formative and that inspired me. I appreciated Jane Austin as a great writer, even though I could not relate to the social issues of her time.
Two books, however, that I despised as a teen and gleefully continue to despise as an adult are Catcher in the Rye and The Great Gatsby. In the unlikely event that a self-important literary critic stumbles upon this blog; there are better books to teach teens about alienation and rebellion. Holden is a whiny brat and should pick a fight with Howard Roark.
As to The Great Gatsby, here is the book review that I never got to write: The pursuit of materialism is a futile endeavor. *Yawn* It is lonely at the top. Never pursue anyone named Daisy. Rosebud. Look what happened to Smeagol.
To those readers who enjoyed two great classics of American literature that I passionately dislike, I am glad that you enjoyed them.
Where was I?
Individual taste and personal choice. It is important to read books that should be part of our collective consciousness, but what I consider to be a great book is a book that is memorable and thought-provoking. It inspires, reveals, introduces new ideas and changes world views.