Sure, we co-opted it from Italy, but pizza is just about as American as apple pie, hot dogs and other calorie-laden fare that makes eating a joy. And while celebrities tend to be at the forefront of the latest sugar-free, carb-free, dairy-free craze, even they can't resist the occasionally slice of cheesy goodness. They eat it at on red carpets, on movie sets, in green rooms and—most spectacularly—at the Academy Awards thanks to host Ellen DeGeneres' cleverly planned bit. 

As a wise woman (cough, Jennifer Lawrence) once said, "Pizza fixes everything."