The York Harbor Inn and The Stageneck Inn up in York Harbor would be my first suggestions....both have nice ambience and The York Harbor Inn always seems to have good food. Check into Stageneck a little more....the dining room overlooks the waves crashing on the rocks just outside the window. 10-12 minutes drive from Kittery.
Anneke Jans is in Kittery and a small hip spot with delicious food and drink....not sure they would be open on Christmas but worth checking out.
60 Wallingford Sq., Kittery, ME 03904
York Harbor Inn
Coastal Route 1A, York Harbor, ME 03911