You all have mentioned some great (bad) ones...I'll nominate "Yummy Yummy Yummy I Got Love in my Tummy" and "Who Let the Dogs Out"
..and the Dave Barry book "Book of Bad Songs" is hilarious!!
Yes it is, vedalisa; and chapgirl, "Havin My Baby" gets a special mention in it for its overall awfulness. He also takes aim at Neil Diamond in the book; particularly for weak lyrics such as those in "I Am I Said". You know,
I am I said
To no one there
And no one heard at all
Not even the chair
To which Dave Barry replies that he wonders why Neil Diamond expects his furniture to listen and respond to him? "Mr. Diamond, your Barcalounger is on line two...".