Lots of great answers, and of course much discussion of the marvellous "Hallelujah" by Leonard Cohen.
My choice for what I wish I had written? today I would go for the brilliant Nick Cave and "God is in the House". I'm with my pal George that the line about "Well-meaning little therapists, Goose-stepping twelve-stepping Tetotalitarianists" - great alliteration!
Awesome song too.