Insel, I was just wondering if it had actually ever been deliberately coined, or just showed up in general usage at a particular time. I popped, "The Best in the World," into Atomica and got this interesting response:

on earth

1. Also, in creation; in the world. Ever, anywhere, of all possible things. These phrases are all used for emphasis in questions or, less often, in a negative context. For example, What on earth is he doing with a spade? or Where in creation did that child go? or How in the world do you expect me to carry all those bags? [Late 1700s]
2. like nothing on earth. Incomparable. For example, That perfume smells like nothing on earth, or Her new hair color is like nothing on earth. [c. 1900]

--The American Heritage Dictionary of Idioms

Like nothing on earth may be the clue to the query here, the original phrase that also became "The Best in the World" and "World Famous." I know like nothing on earth was a favorite call of carnival barkers and the like in the 19th and early 20th centuries. Tough to pinpoint a specific instance of original coinage, though. I'll try "World Famous" and see what turns up.

The Only WO'N!