Dear Jeannine: A lot depends on your age and life style
If you are looking for some laid-back, tranquill and protected time, the Punta Cana is a good choice. Mostly couples, some families, a little older crowd.
Puerto Plata is a little bit different. It is the "gran dame" of the all-inclusives here, but its location permit you to get out and about. Like a 20 minute ride to Sosua and its beach and restaurants (Rocky's !!) or a 6 minute ride into town to see how the old colonies were...Puerto Plata is nearly 500 years old, and it has a charm ofits own.
Cabarete is a swinging town mostly for younger folks that like to party all night and surf, kitesurf or sailboard all day...tons of people looking to have fun...and its just 10 minutes past Sosua..
So take your pick..You should enjoy either of them..
HB