Lyrically, a contender for the worst song ever has got to be "Breakfast at Tiffany's" by Deep Blue Something -- the lyrics and story concept in the song are completely ridiculous.
Essentially, the song is about two people who are breaking up because they have absolutely nothing in common.
But then the guy remembers something: they both liked the film Breakfast at Tiffany's. His girlfriend says she remembers that. Then they reconcile on the basis that they both "kind of like" the movie, so they can now use that as a starting point for rebuilding their relationship.
Seriously, that's the song in a nutshell. Here are the lyrics:
And I said what about Breakfast at Tiffany's
She said I think I remember the film
And as I recall I think we both kind of liked it
And I said well that's the one thing we've got