Good books about Ancient Greece and Rome?

"I, Claudius" by Robert Graves is wonderful

"Claudius was the fourth Emperor of Rome (r. 41-54 A.D.). Historically, Claudius' family kept him out of public life until his sudden coronation at the age of forty nine. This was due to his disabilities, which included a stammer, a limp, and various nervous tics which made him appear mentally deficient to his relatives. This is how he was defined by scholars for most of history, and Graves uses these peculiarities to develop a sympathetic character whose survival in a murderous dynasty depends upon his family's incorrect assumption that he is a harmless idiot.

Graves's interpretation of the story owes much to the histories of Gaius Cornelius Tacitus, Plutarch, and (especially) Suetonius (Lives of the Twelve Caesars). Graves translated Suetonius before writing the novels. Graves claimed that after he read Suetonius, Claudius came to him in a dream one night and demanded that his real story be told. The life of Claudius provided Graves with a way to write about the first four Emperors of Rome (Augustus, Tiberius, Caligula, and Claudius) from an intimate point of view."

http://en.wikipedia.org/wiki/I,_Claudius

One book I swear by si Ronald Syme's "The Roman Revolution", a factual description of the end of the Roman republic and the birth of the Empire. The main figures include Gaius Julius Caesar, Pompey (Pompeius Magnus), Cicero the writer, lawyer and politician, the first emperor, Augustus, the revolutionary Brutus, and Mark Anthony, lover of Cleopatra.

I can't think of any educational books but I'm reading a book atm called Dan Brown - Angels & Demons. It's set in Rome and Vatican City. It's a very good, addictive book, and iI've learned a lot about the country from the book.

Also, read (or play) Assassin's Creed Brotherhood.