If you could provide a little info on your price range and preferred section of town, the hounds could give you some better-tailored recs. In the meantime, here are a few ideas to get the ball rolling:
Expensive to Very Expensive
Boston - No. 9 Park, L'Espalier
Cambridge - Salts, Craigie Street Bistrot
Boston - Grotto, Trattoria Toscana, Ten Tables
Cambridge - Oleana, Chez Henri
Somerville - Gargoyle's, Dali
All of these are discussed quite regularly on the board; if you do a board search, you'll find commentary aplenty.