Here are the top 30 schools in New York state that participated in the Math League contest last year for the sixth grade. The lists for grades seven and eight are similar, but not exact. I've rearranged the list geographically, and noted the "Great School" (GS) rating for all the public schools, which I think makes for more interesting reading.
1 New Exploration into Science Tech & Math New York 165 (Manhattan) (GS10)
2 PS 334 - Anderson School New York 164 (Manhattan) (GS10)
5 Park East Day School New York 150 (Manhattan) (Private - Jewish)
9 Friends Seminary New York 142 (Manhattan) (Private - Quaker)
12 NYC Lab School New York 136 (Manhattan) (GS10)
18 Speyer Legacy School New York 123 (Manhattan) (Private -- Founded in 2009)
20 Ramaz Middle School New York 119 (Manhattan) (Private - Jewish)
21 Grace Church School New York 118 (Manhattan) (Private)
25 Special Music School New York 112 (Manhattan) (GS9)
6 Horace Mann School Bronx 148 (Bronx) (Private)
3 Mark Twain IS 239 Brooklyn 163 (Brooklyn) (GS10)
4 Big Apple Academy Brooklyn 162 (Brooklyn) (Private)
21 Yeshivah of Flatbush Brooklyn 118 (Brooklyn) (Private - Jewish)
25 Poly Prep Country Day School Brooklyn 112 (Brooklyn) (Private)
11 Russell Sage JHS 190 Forest Hills 138 (Queens) (GS9)
14 P.S. 188 - The Kingsbury School Bayside 134 (Queens) (GS10)
29 Daniel Carter Beard JHS 189 Flushing 106 (Queens) (GS7)
7 Oceanside Union Free SD Oceanside 147 (Long Island, Nassau County) (GS9)
9 Shelter Rock ES Manhasset 142 (Long Island, Nassau County) (GS10)
12 Munsey Park ES Manhasset 136 (Long Island, Nassau County) (GS10)
8 Felix V. Festa MS West Nyack 143 (Rockland County) (GS8)
17 Suffern Middle School Suffern 125 (Rockland County) (GS9)
24 Ardsley Middle School Ardsley 116 (Westchester County) (GS9)
16 Iroquois Middle School Niskayuna 126 (Albany / Schenectady suburb) (GS9)
19 Ballston Spa MS Ballston Spa 120 (Saratoga Springs suburb) (GS8)
15 Johanna Perrin MS Fairport 127 (Rochester suburb) (GS9)
21 Martha Brown Middle School Fairport 118 (Rochester suburb) (GS9)
27 Nichols School Buffalo 110 (Buffalo) (Private)
30 Elmwood-Franklin School Buffalo 105 (Buffalo) (Private)
28 Lansing Middle School Lansing 107 (Tompkins County) (GS8)
...
Additional schools taken from 7th and 8th grade contests:
Collegiate School New York (Manhattan) (Private)
Salanter Akiba Riverdale (SAR) Academy Riverdale (Bronx) (Private - Jewish)
Louis Pasteur MS 67 Little Neck (Queens) (GS10)
Baccalaureate Sch. for Global Educ. Astoria (Queens) (GS10)
IS 237--Rachel L. Carson Flushing (Queens) (GS9)
Great Neck North MS Great Neck (Long Island, Nassau County) (GS10)
Jericho MS Jericho (Long Island, Nassau County) (GS10)
Herricks Middle School Albertson (Long Island, Nassau County) (GS10)
Paul J. Gelinas JHS East Setauket (Long Island, Suffolk County) (GS9)
Solomon Schechter School Hartsdale (Westchester County) (Private - Jewish)
Rye Country Day School Rye (Westchester County) (Private)
Sweet Home Middle School Amherst (Buffalo) (GS6) (!)
Jamesville DeWitt MS Jamesville (Syracuse suburb) (GS10)