Hanover St Chophouse - Upscale steakhouse, very good food, traditional in style - definitely on the stuffy side. The sort of place you dress up to go to. Steak is excellent, other stuff is good but not creative.

Forge and Vine - Technically in MA but it's close by. Upscale but not stuffy, farm to table, nice variety of food. It's a hit with my foodie friends too. It strikes a nice balance between having some creativity and some tradition. The nearby Gibbet Hill Grill is also very good and is the best not stuffy steakhouse in the area.

Black Trumpet - Upscale, modern, more interesting food. Smaller portion sizes but you won't leave starving. It's in a nice part of Portsmouth too.

Greenleaf - I feel like my experience there was perhaps not on par with others. I'd definitely be willing to give it another shot. When I was there a couple dishes were great and a couple were meh. Also the waitress felt like she had been hired to work at a diner. So my one experience wasn't flawless but there were definitely bright spots with the food.