By far the Residence Inn, Scarborough, Maine.
Last year we went there for our 10 year anniversary only to have an accident half an hour from the airport, the car was a total write off.
Arrived at the hotel at 2am and got greeted with a smile and the next day they gave us some assistance sorting matters with the insurance. Some little things that made a big difference at the time and where very much appreciated.
Great hotel with fantastic staff and will always be my number one when going to Maine.