Mozza of West Hollywood—hands down my favorite. The crust is insanely good. This place is incredibly popular, so if you're planning to go, be sure to make a reservation ahead of time. Owned by Nancy Silverton (La Brea Bread), the famous Mario Batali and Joseph Bastianich.
Gjelina of Venice Beach—The ambience is a little too surfer yuppie hip for my taste, but delicious pizza. Again, amazing crust. Just a half step behind Mozza.
Village Pizzeria of Hollywood/Larchmont—Brooklyn in style, greasy and delicious.
(This list is incomplete, I will be adding as I go and welcome your suggestions!)