I'm going to mention two that perhaps don't even sell pizza any longer...
I always liked Lax's diablo (spicy) pizza - are they still serving pizza? They had a reasonable menu for a long time, then screwed it up by changing their offerings earlier this year.
Cabarete Blue (on the main street, downstairs immediately east of Villa Taina) had consistently good pizza for about RD$180 for a large pie. They were closed when I was in town a month or so ago. Don't know if just due to slow season or if they're gone for good.
I have to try Pomodoro again. I've heard nothing but good things here and elsewhere, but thought it was horrible earlier this year. That one day was enough to keep me from going back. I stopped there for lunch - perhaps it was the regular chef's day off. Soggy crust, runny sauce, and what I considered to be rather bland cheese.