Ha, my mom says she'll only go to Punta Cana as part of a tour, because one day she'd like to drive around the country, especially the south. My dad's family is from Montecristi. El Morro is a beautiful and very interesting beach and park. I used to go to the river (I think Río Guayubín) since it's a walk away from my grandparents' house.
I also wonder why Samaná, although tourist heavy compared to other places, doesn't get mentioned as much as Puerto Plata and Punta Cana. My mom loves Playa el Valle there. She says it has all these caves and falls where you can kind of hide away. She also loves Las Terrenas. And there's the whale-watching, too. Plus from Samaná you can travel to Cabrera and other parts of the east pretty easily.