Hold it! Lots of discussion about pizza here. Now you might be inclined to believe that pizza is not a sandwich, but hear me out!
Lets start with the definition of sandwich:
"an item of food consisting of two pieces of bread with meat, cheese, or other filling between them, eaten as a light meal."
Cool we've the ingredients. We've got some cheese, some sauce, meats etc...but....
You might already take this at face value and say pizza only has one piece of bread so that can't be categorized as such. But then we'd have to throw out things like heroes where the ingredients are wedged inside of a single piece of bread. And I don't think anyone is going to say a hero isn't just a sandwich.
Ok but pizza still isn't between anything. It's still just a piece of bread with stuff sitting on top of it.
Wrong again, pizza plebs! I introduce you to the New York fold. The only proper way to eat pizza:
Look at that, the ingredients all sandwiched neatly and flavorfully between the bread!
I would say based on the above evidence, and the New York (correct) way to eat pizza, that pizza is in fact, a sandwhich.
Anyway, hot dogs are clearly the best sandwich.