Which disqualifies Bon Jovi's "Blaze of Glory" and super-qualifies Prince's "Batdance."
"On Our Own" gets my vote because:
1. The first verse is just the plot of the movie.
2. If you ignore the initial ghostbusting verse, the bridges/choruses could be from any number of R&B jams. For as much as the first verse was about busting ghosts, these are markedly not ghost-aware.
3. The final verse is just a repeat of the first verse.
Stev D: [calling to his wife, to no one, to everyone] I am a starred commenter. Don't forget that.