This thing is 50 years old now. I've just started reading it for the first time. Not very far in, but it's definitely interesting.

A line from the Washington Post review:

When Victor Marchetti's The CIA and the Cult of Intelligence was published it contained intriguing blanks where material deemed too sensitive by the CIA had been.
There are no blanks in Philip Agee's Inside the Company: CIA Diary.

There's a PDF available here if anyone wants to read it.