If you want a vacation, would recommend that you stick to the southeast. There is enough to see and do from Santo Domingo all the way to Bayahibe.
Drive through Boca Chica to see the beach. If you like a surfing beach, check out Caribbean Sun (Playa Caribe)-- if it is before noon -- in the afternoon (and on weekends, it gets crowded. If it is a weekday, it will be quite empty and enjoyable.
Other options is the new Aura in Juan Dolio. Do a search for photos in this forum.
As you tour through this area, check out the hotels on the way. Lots of small ones, too. Try to get a rate that will be low enough so you wont mind doing meals outside the hotel.
There are a bunch of good restaurants -- Meson (for Spanish food), El Ensueño for Italian, La Cucina de la Mamma for Italian...
Then head for La Romana and Bayahibe. The best Bayahibe beach is in the Dominicus area, between Wyndham Viva Dominicus Palace and Iberostar Hacienda (it is a public beach strip).
Tour La Romana (Altos de Chavon, Marina de Casa de Campo) and the town.
For listings of hotels in these areas see:
http://dr1.com/directories/index.shtml