Reddit reviews Boss of Bosses: The Fall of the Godfather- The FBI and Paul Castellano

Underboss is great because unlike Hill's account in Wiseguy, Sammy the Bull wasn't an associate. He was a mademan and became underboss briefly towards the end of Gott's reign.
http://www.amazon.com/Underboss-Peter-Maas/dp/0061096644

The Westies is fascinating because it details a crime org other than the Italian mafia.
http://www.amazon.com/Westies-Inside-New-Yorks-Irish/dp/0312924291

The Born to Kill gang is another fascinating one. However, they weren't that organized.
http://www.amazon.com/Born-Kill-Notorious-Vietnamese-Organized/dp/0688122388

The Man Who Made it Snow is about Max Mermelstein who trafficked cocaine in the 80s. He was involved in the events discussed in the doc Cocaine Cowboys.
http://www.amazon.com/Man-Who-Made-Snow/dp/0671703129

Boss of Bosses is told from the FBI's point of view as they try to get Paul Costellano.
http://www.amazon.com/Boss-Bosses-FBI-Paul-Castellano/dp/0440212294

Here are the best historical Mafia books that I can recall off the top of my head:

Boss of Bosses - About the killing of one of the last true old school mafia bosses

Wiseguy - The book that Goodfellas is based on.

The Westies - About the Irish New York Mob

The Valachi Papers - from the 60's. One of the first to expose the mafia and its tropes to the greater public

His brother's name was "Chuck Giancana", and he co-wrote the book Double Cross: The Explosive Inside Story of the Mobster Who Controlled America along with his son and brother's namesake "Sam Giancana".

As for the book name, The Boss of Bosses: The Life of the Infamous Toto Riina Dreaded Head of the Sicilian Mafia
and
Boss of Bosses: The Fall of the Godfather- The FBI and Paul Castellano weren't written by or about a "Giancana".