I nominate Animal Farm by George Orwell.
ANIMAL FARM is a short novel that can be read in a single two-hour sitting. The name seems to imply a children's novel, indeed the words are simple enough, but the satire is thick on every page. This novel is a companion to Orwell's equally famous novel, NINETEEN EIGHTY-FOUR. Both are essential reading.
Animal Farm is the most famous satirical allegory of Soviet totalitarianism. Published in 1945, the book reflects events leading up to and during the Stalin era. Orwell, a democratic socialist, and a member of the Independent Labour Party for many years, was a critic of Joseph Stalin, and was suspicious of Moscow-directed Stalinism after his experiences with the NKVD during the Spanish Civil War.
The book was chosen by Time Magazine as one of the 100 best English language novels (1923 to 2005) and was number 31 on the Modern Library List of Best 20th Century Novels.
The novel describes how a society's ideologies can be manipulated and twisted by individuals in positions of social and political power, including how a utopian society is made impossible by the corrupting nature of the very power necessary to create it.