Although these Brazilian ads are not really nonprofit (The governement wants you to pay taxes) I like the comic style.
These ads are from the Corpo de Bombeiros Militar, the Military Fire Corps.
Translation of the copy:
Big orange title: Help the real world super heros to save lives. Pay the fire tax.
White box of text: When you pay the fire tax, you’re helping the biggest heros of our society to save many lives. Your contribution is essencial to reequip the fire-men corps in the area of rescue, combat and prevention of fires, with ambulances, helicopters, vehicles, uniforms and hoses among others.
Yellow box of text: Save lives whitout risking your own. Pay the fire tax
Car box: And now… Pay your taxes on date and win a car.
Many thans to Carla Ribeiro for the translation.