I am not a regular member of Park Street Church, but I do attend every so often. The Pastor, Dr. Gordon Hugenberger, is amazing. I always leave feeling moved and challenged. Even though this is a city where everyone is an academic and an intellectual, it is often difficult to find church that feeds this type of mind, but the Park Street Church always seems to give you something to think about - it is never the same old "ho hum" sermon. For those shopping around for something new, I would highly recommend checking it out.
It is a Christian, Congregational Church, for those interested in the denomination.