"Tonight" (Iggy Pop)

The better known version of this David Bowie-Iggy Pop composition is from the Bowie album of the same name.  He recut the song in 1984 as a reggae-flavored duet with Tina Turner during his "I want to be a mainstream pop star" period.  It's about as cringe-inducing as you might imagine.  (Not quite as bad as his "Dancing in the Street" debacle with Jagger from '85, but it's close.)
Pop's version from the album Lust for Life (1977) is worlds apart.  It begins with a chilling monologue, which has Iggy watching his girlfriend turn blue from a heroin overdose as he emphatically vows to her that everything will turn out okay (even though all signs indicate it won't).
His delivery is incredibly poetic and tender--crooning even, and his incomparable band (which consists of Bowie on keys and backing vocals, crack guitarists Carlos Alomar and Ricky Gardiner, and the rhythm assault team of brothers Tony and Hunt Sales on bass and drums, respectively) backs Iggy with an urgency that belies the gravity of the subject matter, tinged with a heavy dose of romanticism.  It's like a majestic yet visceral update of a 1950s "teenage tragedy" ballad.
Everything I love about this track comes to a head on the song's bridge, with Alomar's guitar wailing over Tony Sales's hyper-melodic bassline (which refuses to hang out on the same note for more than a second; it's one of my favorite performances on electric bass) and Hunt Sales's thunderous drumming (lesser drummers could only dream about the syncopated stuff he's doing with his double bass pedal on that bridge).