The Gatekeepers is a fascinating inside baseball account of the Presidential administrations going back to Richard Nixon. You learn a lot about the inner workings of the White House and how major policy things were done. With all the quotes from the principals and some background staffers, Chris Whipple must have spent hundreds of hours in interviews. In some places it's a bit surface and his political biases show through, but overall it's well written and engaging.
Recommended for political junkies of any stripe.