20. Hip-Hop Revolution: The Culture and Politics of Rap (Cultureamerica) by Jeffrey Ogbonna Green Ogbar
19. The Hip Hop Wars: What We Talk About When We Talk About Hip Hop--and Why It Matters by Tricia Rose
17. Hiding in Hip Hop: On the Down Low in the Entertainment Industry--from Music to Hollywood by Terrance Dean
11. Somebody Scream!: Rap Music's Rise to Prominence in the Aftershock of Black Power by Marcus Reeves
8. The Hip Hop Generation: Young Blacks and the Crisis in African American Culture by Bakari Kitwana
3. Notorious C.O.P.: The Inside Story of the Tupac, Biggie, and Jam Master Jay Investigations from NYPD's First "Hip-Hop Cop" by Derrick Parker, and Matt Diehl
If I forget any please let me know so I can expand this to a top 25 and maybe even a top 50...