This thread is so surprisingly interesting - the variations are all over the place and yet anchoring it is a solid contingency who has no idea what’s going down! Who woulda thought?
Central MD here, and like many of the posters (or it was a little selective bias on my part):
Lightbulb
Pinnocchio
Monopoly
George Washington
Lepke.
Age 28, Male, Northern Arkansas. I’ve always heard “Columbus”
In my aesthetic opinion, “George Washington” has two many syllables. Sure, it’s technically the same number as “Monopoly” or “Pinocchio,” but neither of those have a first syllable is rather consonant heavy and makes the whole thing sound all crammed together. “George” may be an unstressed syllable, but it’s not that unstressed.
You said it yourself. “Natural History.” Without qualifications, most academics use “history” to mean “written history.” They call the stuff that comes before writing “prehistory.”
Of course you’re going to see that type of pedantry here! 
Missed this the first time. That’s the perfect four syllable word. It has two stressed syllables, like all the other callbacks. That makes it fit better than “Columbus,” IMHO.
I’ve always felt that “Columbus” didn’t quite fit, so thanks for helping me figure out why. The “bus” syllable is stressed, which sounds weird.
California in the 80s/90s and it was lightbulb, pinnochio, monopoly, and Columbus.
I grew up across Canada (Air Force brat) with most of my time in Alberta and Manitoba and we used to end with “like Charlieeee Bbrrrrroooowwwnnnn”.
Others were light bulb, dumbo, and monopoly.
George Washington. Michigan.
Mrs. Mahaloth is from California and she learned:
Hitler
I thought she was joking, but she swears this is what she sang as a kid.
Lightbulb
Dumbo
Football
Columbus
Texas
I never knew there were variations, either. Now I’m wondering about variations on “Jingle Bells, Batman Smells”.
Columbus. I’m from Texas.