I enjoy mafia fiction sometimes more then non fiction bcuz I'm not fact checking it.

Here's some good ones....
Trinities (Forgot author name be also wrote King Of The Jews about Arnold rothstein.)

Live By Night by Dennis Lehane

CHARLIE STELLA wrote a few mafia books that are Elmore Leonard style

Blood Of Our Fathers (never read the sequel but this book was excellent)

All four of the Prizzi books were great.

CHINA WHITE by Peter Mass was good (triad book)

And several more I can't think of right now.