Of course, here on Earth, it’s the bowling ball. But why?
The answer is air resistance. Those darn air particles slow down the low mass feathers. They try to slow down the high mass bowling ball, but have little effect. So the feathers take longer to fall.
But what if you could remove those pesky air particles? Well, they did this on one of the later Apollo missions, but you can also do this on Earth. If you have the right equipment. Fortunately, NASA does.