•Why it earns a slot
The play gives Western literature its defining portrait of political self-deception, showing how Brutus's conviction that a noble motive purifies a violent act leads directly to the tyranny and civil war he meant to prevent, while Antony's Forum speech remains the canonical dramatic study of rhetoric manipulating a crowd.
A group of Roman senators, led by the idealistic Brutus and the scheming Cassius, assassinate Julius Caesar on the Ides of March to prevent him from becoming a tyrant. Caesar's ally Mark Antony then turns the Roman populace against the conspirators with a masterful funeral oration, driving Brutus and Cassius into civil war. Both men die by their own swords at the Battle of Philippi, and Antony eulogizes Brutus as the noblest Roman of them all.
This distillation is written from the freely available original, which is always the better read when you have the time: gutenberg.org.