Los Hermanos Rosario, To?o Rosario solo also has a few good ones, Los Toros Band is one of my favorites, also Alex Bueno, Monchi y Alexandra, Aventura (PR group) has a couple that I like, Zaccarias Ferreira has a lot of really great songs, Juan Luis Guerra is awesome, Fernando Villalona (El Mayimbe en Bachata is my favorite), Jossie Esteban, El Gringo de la Bachata, Eddy Herrera, Rubby Perez, Yoskar Sarante, and Antony Santos to name a few. Great picks above, add these names, and you have a pretty great collection. I found a website that keeps quite current with Dominican music trends. It lets you listen to popular songs from the discography of artists listed. Frank Reyes is my favorite as of late. I know I may offend a lot of people by saying this (my husband included), but I can't stand Luis Vargas' whining...like cry me a river...but that's my opinion...he's certainly still one of the most popular.
http://home-3.tiscali.nl/~pjetax/htmlfile/music_index.html