A great place all around
This is definitely a Boston classic - and the Park Square location is great for singles, couples or families. There are two levels of seating - the main floor has booths and tables; downstairs is a little more formal, with seating right in the wine rooms.
While there's always the classics for adults, there's a great kids menu that includes pizza, hamburgers, macaroni and cheese, fish sticks, etc. It's very kid/family-friendly.
The service is great - servers know a lot about the different kinds of fish. And I'd recommend trying something new off the huge wine list - the servers are good with recommending wines to go with different sorts of dishes.