"'Heroes'" (David Bowie)

David Bowie had gotten his fill of fame and its vices.  So he left the glitz and drugs behind and relocated to Berlin in 1976, drawn by the city's Cold War-era austerity.  In time, he was joined by longtime collaborator/producer Tony Visconti and musician Brian Eno and, together, they created a trilogy of challenging, groundbreaking albums (Low, 'Heroes', and Lodger) that still sound unbelievably fresh today.
All three records, incidentally, were recorded at Hansa Studios, which sat within view of the Berlin Wall, or the "Wall of Shame" as it had been dubbed by the West.  One afternoon while staring out the window of the studio's control room, Bowie happened to catch Visconti passionately kissing a young woman (who wasn't Visconti's wife) beneath a guard turret on the Wall.  On the one hand, Bowie saw their act as heroic: they weren't allowing the very real danger of being shot by guards deter them from freely expressing their very real affection for one another.  On the other hand, he surmised that they were meeting in such a dangerous place because they felt guilty about the affair, and they were psychologically justifying their rendezvous as an act of "heroism."
The incident inspired Bowie to pen "'Heroes'", an intensely emotional, complicated portrait of ill-fated love winning a victory over oppression for a fleeting moment (hence the ironic quotation marks in the song's title).  
Although every note of this song is electrifying, my favorite moment comes in the second verse, as Bowie nearly cries the words And the shame was on the other side.  It's such a smart bit of wordplay, referring not only to the lovers' literal location in the shadow of the "Wall of Shame" but also the feelings of self-reproach that they're attempting to put aside.
In short, this is the song that made me a Bowie fan for life.