Thinking a little more about the title of this thread. Could it be expanded to something like this -- "Books that responsible people in modern society should read"? If so, just about the first thing that would come to mind would be Solzhenitsyn's One Day in the Life of Ivan Denisovich. If you have any interest in understanding our time, you need to understand totalitarianism, which, I would say, is a distinctively modern phenomenon and one that has cost more people more suffering, or indeed their lives, than any of the other miserable -isms, yes, including colonialism, racism, sexism, etc. Totalitarianism is the embodiment of the complete subjugation of the person and society to ideology -- could be Maoism, Nazism, Soviet communism, Islamofascism, etc. It would eradicate the past, thoroughly pervade the present, supposedly for the sake of a future renewal of humanity. There are certainly more thorough books relating to totalitarianism, but One Day may be read in one day as a convincing story of life in a totalitarian society.
After reading it, I would recommend a less well-known book, Sebastian Haffner's fairly brief account of the Nazification of a city, Defying Hitler. But perhaps The Diary of Anne Frank would be a better choice for some readers.