Worlds Best - World's Best???

Learned from About Last Night that the Chicago Manual of Style has its own website.

Apparently you can post questions and the editors respond. OGIC from About Last Night read all the archived comments, and posted this one:

Although the sign was incorrect, I’m not sure you should annoy the person who provides the enchiladas.

This brought to mind a co-worker of the Hobbled Wife whose biggest pet-peeve was (is?) business signs with incorrect grammar.