Two thumbs up for Hotel Palacio! I have stayed there many times in the past. Reasonable prices, German owner so everything works, nice staff, historical building, and only 1/2 block to El Conde. http:dominican-rep.com/Hotel-Palacio.html
Another good hotel is the Hotel Conde de Peñalba at the Cathedral's end of El Conde.
www.condepenalba.com
P.S. All of the hotels on the Malecon have an agreement with the tourism group saying no dominican 'guests', either for a short time or overnight. That includes the InterContinental, the Melia, the Jaragua, Hotel Santo Domingo, the Hilton, and supposedly the Napolitano.