"Fight the Power" (Public Enemy)

Public Enemy may well have been the pinnacle of hip hop.  
On the one hand, you had brothers Hank and Keith Shocklee coming up with these sublimely funky rhythm/backing tracks for every single track.  In fact, you can't even call what they were doing "sampling"; they were creating complex sound collages from carefully selected breaks and snippets, which were then strategically placed in a mosaic to create textures and evoke moods.  (I mean, there's a reason why James Brown's "Funky President" shows up in the middle of "Fight the Power.") 
Add to that Chuck D, perhaps the most thought-provoking, professorial emcee ever, and consummate class clown Flava Flav, and you had a group that picked up where Grandmaster Flash & The Furious Five's "The Message" left off and took the commentary a step further.  The message was: let's not just rap about our situation; let's get our shit together and change the situation.
"Fight the Power" essentially was commissioned by Spike Lee for his 1989 film, Do the Right Thing.  Lee wanted a song—an anthem—that the character "Radio Raheem" would be playing on his boombox, every time he appeared on screen.
Inspired by the 1975 Isley Brothers song of the same name, Chuck D began with the theme of "Fight the Power."  From there, he wrote the bulk of the lyrics, which bluntly address double standards and disenfranchisement, while on a flight to Europe to support Run-D.M.C. on their Fall 1988 tour.
The track caused a bit of controversy because of Chuck's specific mention of Elvis Presley and John Wayne in the lyrics.  (He calls them both "racists.")  Although, as he explained to Rolling Stone in June 2014, his commentary was less about Presley and Wayne, per se, and more about society’s idolization of white "American heroes" while black leaders and innovators often were overlooked.
"It's not that Elvis was not a talented dude and incredible in his way, but I didn't like the way that he was talked about all the time, and the pioneers (of rock & roll), especially at that time, weren't talked about at all."
I'd say Spike Lee got his anthem and then some.