For me there are 2 probably.
If You're Feeling Sinister by Belle & Sebastian
"If you are feeling sinister, go up and see a minister, the chances are you'd probably feel better if you stayed and played with yourself".
Love how that line manages to feel stuffed with childlike naivety and intense cynicism at the same time.

The National - Karen
"Karen, we should call your father, maybe it's just a phase
He'll know the trick to get a wayward soul to change his ways
It's a common fetish for a doting man
to ballerina on the coffee table cock in hand".
It made me laugh a bit when I heard it, especially when coupled with the quite sedate music. The whole song just sounds really well written.