You should go to the houlihanlawrence website and there is a search function that should allow you to search by the school district (don't go by town names as different school districts encompass different towns and vice versa). Choose these school districts as their reputations are excellent, have excellent statistics, (and are listed in US News & World as top schools.
Top 100 Public HS in the US ranking includes (in order are):
Edgement High (this is part of Scarsdale)
Horace Greeley - in Chappaqua School District so choose Chappaqua on the drop down box.
Blind Brook (in Rye Brook)
Within the Top 400 Public HS in the US
Byram Hills - (encompasses Armonk/parts of Bedford & Chappaqua)
Briarcliff - (encompasses parts of Briarcliff Manor, Pleasantville, etc.)
While not in the ranking, Bronxville, John Jay, Somers, Hendrick Hudson, Fox Lane, Pelham are all pretty good too.
Make sure you choose by school district because it gets confusing. For example, just because you're in Chappaqua does not mean you will go to Horace Greeley - some go to Byram Hills or Yorktown. And some parts of Mount Kisco go to Horace Greeley while others go to Fox Lane, etc.... Good luck!