I travel to the Hartford area frequently and enjoy City Fish Market at 884 Silas Deane Highway in Wethersfield, CT. (about 30 min S. of the airport) It’s not fancy but very clean and the guys are very helpful and friendly. You order at the counter and take your food into the dining room at the front. If you are there during soft shell crab season try them – they are amazing! This is where the natives eat, it’s been named "Best of Hartford" for 15 years.
There is also a great lunch restaurant a few blocks south – Max Bibo’s @691 Silas Dean Hwy. Picnic food, superb sandwiches, innovative food cooked on premises. I eat there every day when I am in Hartford.