I have stayed at Atarazana, Mercure, Carey House, Jaragua, and Hotel Venezia.
Hotel Mercure is centrally located right on El Conde. Book online and pay in advance the rate is about $60 USD with taxes.
Hotel Mercure Comercial Santo Domingo: book your Mercure hotel in SANTO DOMINGO
Hotel Atarazana is in a very quiet area about two blocks from Plaza Espana. Probably not the best location if you intend to go out late at night.
hotel-atarazana
Carey House Hotel, again another hotel in a quiet residencial area.
.::Welcome to carey House Hotel::.
Jaragua Hotel/Casino is top shelf if you want the tall modern hotel with a casino.
The Renaissance Jaragua Hotel & Casino: A luxury hotel in Santo Domingo
Hotel Venezia is located a few blocks from Parque Indenpendencia and maybe 5 blocks to Pacos Restaurante.
located in the heart of Santo Domingo
I think you might enjoy Hotel Mercure. Walk out the front door and you smack dab in the middles of Zona Colonial. There is also a small club, Nowhere, right across the street. The price you pay for the room also includes a free buffet breakfast.
A good source of information on Zona Colonial is:
The Complete Guide to Colonial Zone, Santo Domingo, Dominican Republic. Tourist Information, Restaurants, Night Life, Hotels, History, Monuments, Maps, Music, Businesses, Folklore, Calendar, Language and So Much More.