One Day in the Life of Ivan Denisovich (1962): Fictionalized prison memoir provides an examination of life in a Stalinist labor camp after WWII. Well worth reading for unexpected points like work satisfaction, class distinctions, and admiration of the Latvians for being stand-up guys (I lived in Riga 1994-97 so I twig on things Latvian).
The First Circle (1968): People with special technical skills were incarcerated in special labor camps in the USSR of the 1950s. This compelling novel is about people in impossible circumstances doing what they can to preserve their own souls and dignity. As one of the great novels of the 20th century it should be approached with respect but not trepidation. It’s a real page turner, the novel that convinced me how great a story-teller AS was.
The Cancer Ward (1968): Set in a cancer ward in Tashkent, it is about politics, of course, but it is also an illness memoir, from the anxiety of diagnosis to iatrogenic problems. Extremely readable, an amazing novel.
August 1914 (1971): Long stretches are rather tedious so I can recommend only to serious students of WWI. The novel centers on the disastrous loss in the Battle of Tannenberg at the time mentioned in the title.