Much easier to give you a useful answer if you give some parameters: fine or casual dining, types of food, etc, but here are our favorites in the area, all reliably good.
Bia, Cohasset http://www.biabistro.com/
Square Café, Hingham http://www.thesquarecafe.com/main.shtml
Tosca or Caffe Tosca, Hingham http://www.eatwellinc.com/
Bridgeman’s, Nantasket http://www.bridgemansrestaurant.com/
Jake’s, Nantasket http://www.jakesseafoods.com/
Also, very near the Music Circus on 3A in Cohasset is a basic suburban pan-Asian place called Feng Shui which is perfectly acceptable although certainly not memorable.