Davey,For me its the honesty in the lyric more than anything else. A catchy tune is cute, "Happy Birthday Sweet 16" catchy little lyric very comercial but like popcorn gone very soon after the experience. "I Come And Stand At Every Door" has haunted me from the first time I heard it.
Honesty in humor is just as powerful, "Donald and Lydia" or "The Mountains of Mourne" Both tragicomic, both brilliant and both honest in their sentiment.
Its the honesty that draws me to a song.
Don