I have read seven books about ancient Rome over the past year.
The Fall of Rome: And the End of Civilization, by Bryan Ward-Perkins
24 Hours in Ancient Rome: A Day in the Life of the People Who Lived There, by Philip Matyszak
The Dream of Rome by Boris Johnson, by Boris Johnson
Pax Romana: War, Peace and Conquest in the Roman World, by Adrian Goldsworthy
The Roman Republic: A Very Short Introduction, by David M. Gwynn
I have read the following books in Italian:
Storia di Roma antica, by Giuseppe Antonelli
Una giornata nell'antica Roma. Vita quotidiana, segreti e curiosità, by Alberto Angela
All of them were good, but The Fall of Rome was the least interesting for me, maybe because I already knew well that period and didn't learn much.
Boris Johnson's book was quite enjoyable because it was very funny, while at the same time being well-written and erudite.
But my favourite in the lot has to be the last one by Alberto Angela, which also exists in English (A Day in the Life of Ancient Rome).
If you had to read only two books I would recommend these two. Unfortunately Boris Johnson's book isn't available on Kindle.