In no particular order
For STEM: Exeter, Choate, Hotchkiss
For Humanities: Andover, Lawrenceville, Deerfield
My son attended Lville and was more of a STEM based kid when he started. But by the time he finished, he was more focused on the humanities. It may have been due to the teaching style (Harkness) but overall I agree with the others. All of the schools above are wonderful, and each has their own strengths/weaknesses.