And about two other books in related categories:
A classic that, on rereading, disappointed:Read more about Neil deGrasse Tyson's most important books.
George Orwell's 1984. Why I would believe it would be interesting beyond the date, I don't know. In the 1970s it was scary. By the 1990s it was quaint. You almost can't blame it.
A Certified Important Book you haven't read:
War and Peace by Leo Tolstoy. For not having read it, I feel I may be a little undereducated. I could be missing some insight into the human condition, because after all, what is life but the interplay between war and peace?