I would recommend looking at https://coachamerica.com/destinations/boston . They have minivans for up to 15 people and coach buses for up to 56 people, which is convenient for family trips. You can choose bus with comfortable seats, a toilet, and Wi-Fi, and booking takes only a few minutes. Managers will help you create a route around Boston and the surrounding area, including attractions such as Freedom Trail or Fenway Park. The drivers are professional, they know the city and provide safe travel. We used their services and were satisfied: everything is convenient, comfortable, and the price is known in advance.