Pizza deserves to be it's own food group.
I don't like a lot of crap on mine, just cheese or pepperoni, and I love a good Hawaiian from some places.
Domino's deep dish is amazing, because it has a layer of spices on the bottom.
Pizza Hut is fail, because it's thin, greasy, tastes like meat byproducts, and the crust is sponge-like and soggy.
Local places make the best pizza, IMO. They usually taste the closest to homemade.
I also think the sauce and crust are the biggest determining factors in whether a pizza is good or not.