Take a look at the thread called Humorous songs.

One I posted there is Lou and Peter Berryman's Here's Louie With The Sports. It's like a lot of Berryman songs, in that it sneaks up on you. The first verse seems kind of pointless (or, depending on the song, incomprehensible). By the second verse, you begin to see what they're getting at, and it makes you smile. By the third verse, they're getting really over the top, so you laugh. By the last verse, you're ROFL.