I take my LR3 to the dealer I bought it from in NH. Bedford Land Rover in Bedford, NH. They do great work, are very fair, and I trust their work. However, it's not the South Shore or even North Shore but is about 30 minutes North of Boston.
For general repair and maintenance I also recommend Spark's Automotive Car Care on Lebanon St. in Melrose, MA. I do not recommend the Land Rover dealership on RTE 1 in Danvers/Peabody.