I can't believe I read the whole thing.

Long-running supermarket add from deep in the heart of Dixie:
From the welcome, to the checkout,
You're in a better mood,
When you're in a Piggly Wiggly,
Buying Piggly Wiggly food.

The worst one I ever wrote, a radio commercial for a local rug merchant to the tune of the Battle Hymn of the Repubic, started off:
Mine eyes have seen the glory of a rug that's sold by Ford,
They are clearing out the warehouse where the rolls of rugs are stored...
Thankfully I can't remember any more of it.
- Phil