I try to stay with one slice of crust with double the cheese and toppings, taking 2 slices and removing the good stuff to double up the other, and discarding the unloved crust.
At one time a friend used to just want the crust, no good stuff. It worked out well as I could double down my toppings without wasting anything.
I knew a guy in college who wanted to market the “Bucket of Toppings”. No crust at all.
All of them
A standard New York City Neapolitan pizza is 18 inches in diameter, although the “Nonna” rectangular style (richer and oilier, like a New Haven pizza) is making inroads.
When I was a fairly strong young rose, I could handle four slices. At my advanced age, 2 or 3, depending on my hunger or gluttony. There’s a place about a block and a half away that makes the best pizza outside of Naples or Wooster Street, according to our entire family, so it’s usually three.
The rest gets wrapped in foil and stowed in the fridge. Ten minutes in a 350 oven restores it to its former glory in the form of a late-night snack. And gives me “Dreams of the Rarebit Fiend” style nightmares.
I for one am glad to see the return of this.
How many you got?
I usually scarf down pizza like there’s no tomorrow. I can polish off a medium pizza by myself no problem. Now, a large…there *might *be a couple of slices left over for breakfast.
I cut my pizza like a Mercedes star. If its really big, I might go BMW rondel.
Nope.
I’m a little surprised by the answers here. I’m a big guy who likes his pizza but two slices is my standard order and I’m full after that.
Generally two slices. If I’m to have any hope of consuming a significant amount of any side dish, one. My appetite is pretty small.
One. Occasionally, I buy a Little Caesar’s Hot and Now, which comes cut in eight slices. I put them in the fridge, and for lunch, I reheat a slice a day until it’s gone. Usually with a tomato on the side.
3 slices from a medium. 2 if it’s a large pizza.
I don’t eat any sides with pizza. I’m focused entirely on pizza.
1-2 slices
Slices? What slices? The only pizza I eat these days are the frozen pizzas. I fold the whole thing over and eat it like a big taco.
Costco combo - one slice, maybe two if I’m starving (not actually starving- you know, really hungry). For other pizzas, about similiar square footage.
I take a night off from cooking a couple times a month, and that often means pizza night. I usually have one, maybe two slices. At first. But a couple hours later I’ll inevitably wander back toward the kitchen and have some more. 
Maybe with hot sauce or some other condiment.
Three or four. If I order pizza at home for lunch/dinner it lasts 3 or 4 days.
I love pizza. I eat until the pizza and my dignity are both gone.
Pretty much this. I don’t even share pizza any more. As in, if there’s a group, such as when we order in for lunch at work, I’ll always get my own small one (which I always think “I’ll have some for later” and then I proceed to deep throat the whole thing. Mine, mine, mine.