It's not pizza without pepperoni. :P
The ideal pizza, imo, has: pepperoni, sausage, bell peppers, onions, black olives, and mushrooms.
The only toppings I am vehemently against are fruits (pineapple, etc.). I do not want sickly sweet fruits anywhere near my meats, ever.
And I'm pro-anchovy.
Also, imo, there really isn't any such thing as a bad pizza (except one with sickly sweet fruit on it).