I like the pharase of Guest, Joe's:

"worst line that fails to ruin a good song" because I really like the next two songs:

Bonepony, a wonderful rockabilly song:

"There is a sacred spot upon a mountaintop
Beside a river flows, and it don't ever stop"

Well, obviously, that river isn't flowing on the mountaintop.

I am a devotee of the work of Dan Bern. I recall that in one of his songs he reaches the end with: "I've got to go I need a shave" to get out of it.