I grew up and lived in Suffolk County and still have connections. Best school districts as follows: Huntington, Woodbury, Cold Spring Harbor, Dix Hills, etc. As a guideline, the easy way is to go by the price of homes. The more expensive the homes are, the better the school district; the lower the prices of homes, the lower the qualify of school districts.
In the New York City suburbs (Nassau, Suffolk, Westchester, Rockland and New Jersey) it's all about the quality of the public school districts. In ALL the suburbs, homes are priced according to the ranking of school districts. Schools that are highly ranked and excellent quality are where all the expensive homes are. Schools that are ranked low and need improvement are where all the cheap homes are.
Unfortunately this is what makes buyers angry. Everybody wants to live in the good school districts but can't afford it. If this is you, you will need to compromise and sacrifice like everybody else does. What we did was buy a co-op so our kids could be educated in a top school district.