I've visited Samana in the Dominican Republic twice. Both times were day excursions as part of a cruise. The first time we went to a resort beach (I don't remember the name of the resort) and then did some shopping. This excursion was just okay. We drove through the city of Samana and got a glimpse of what life for the people is like, but we didn't really interact with them much. The resort beach was very pretty though and we had a great swim.
On our second visit a couple years later, we decided to do a rain forest/waterfall hike. This was a neat experience. We had a tour guide and then there were other locals that went with us as well to talk to us about their culture. Their english was poor and my spanish was poor, but I still learned a lot. Our guide stopped to show us different plants and we even saw a large snake. We were able to swim in the waterfall and it was a lot of fun.