Foote School in New Haven goes K-9 and Hamden Hall goes K-12. My son attended Foote G6-9 and then HH 10-12. HH is a little less intense (Foote is where all the Yale faculty brats go) but it depends on the kid. All things considered, I think the better bet would be HH. The kids at Foote probably think of Shelton as being way, way out in the sticks. Those are the only ones I have actual knowledge of. Fairfield County, of course, has a shit-ton of schools, which may be more convenient than schlepping your kid to New Haven.