Champs Elysées is probably the worst place to eat a Pizza.
The ones that are on the Avenue are at best common and at worst gross.
But if you're still down for a pizza the only place worth trying would be Pazzo .
They propose the Pizza Romana ( al Taglio ) , the pizza dow is perfect and perfectly done ( 48h hours rest ) which give them the great taste of straight from the oven "baguette"
the recepies are classic and the "taglio" system gives you the possibility to try as many as you want.