1938 Johnny "Double No-Hit" Vander Meer Huskies Ad. I have posted a photo of this one before on another thread, but it fits here.
Ironically, I just upgraded mine yesterday to one in unbelievable condition considering its age. The image below is my new upgrade. To quote Perezfan Mark, this one is "frameworthy".
To those that are interested, eBay seller looseleaf1234 seems to be selling an incredible collection of early ad items like these right now.