I once heard someone say that Janet Jackson was a guilty pleasure. If I ever have to feel guilty about liking this song, someone smack me in the face and tell me to get it together, because this song slays.
Rhythm Nation 1814 was a hugely successful album about social injustice that A&M Records didn't want Janet Jackson to make. She and her production/writing team of Jimmy Jam and Terry Lewis knew better -- the album has sold over 12 million copies and consistently makes lists of the Top 100 albums of all time. The title track is without a doubt the heaviest hit of 1989, and it never once got a spin on Headbangers Ball.
Particularly unique about this song is the fact that it's just one chord (E). There's not a single chord change in this song, which makes its wealth of emotion and energy particularly stunning. The only other one-chorders I can think of are Eddy Grant's "Electric Avenue," Placebo's "Pure Morning," Beck's "Loser," and "Love You To" by the Beatles. Speak up, musos! What am I missing?