Here are my favorites:
Polvorones: a heavy, soft crumbly cookie that has some type of cinnamon in them. They are yummilicious.
Rice and Beans: I'm sure there is a Dominican word that I'm missing for "Rice and Beans" but OMG delicious. Especially since the rice fields are a few miles away from the actual store.
Tostones: Fried, salted plantains.
Crab or Squid Empanadas: I had these excellent empanadas at Meson D'Bari in Santo Domingo. Mouthwatering sea food in a pocket of fried love.
Mangoes, Bananas, Coconuts, literally any fruit with a peel that you can get your hands on will be the most delicious, juicy thing you will ever eat.
I also ate some kind of lemon square that I was fond of and some really great steak, eggs, and pork. Also some pasta thing with clams in it. Yum.
Needless to say upon my return to the US my stomach had a rocky road to face with all the hormones, preservatives and additives we have in the food in this country. Good thing you can actually use the toilets here and have a hot shower since both of those were needed for my angry stomach.