Margherita, as the queen and the flower (‘daisy’).
Simple and patriotic.
With mozzarella fiordilatte or mozzarella di bufala
maybe some olio piccante
Capricciosa (capricious’), with prosciutto cotto (‘ham’), parmigiano, basil, black olives, mushrooms and artichokes
Quattro stagioni (‘four seasons’), normally the same ingredients of the capricciosa, but each one on its quarter
Caprese, with fresh tomato and mozzarella
(See also “I miss 100(and more) shades of pizza – 1 -2” https://misshome.wordpress.com/2014/01/25/207-i-miss-100and-more-shades-of-pizza/