1. Centerport/Greenlawn (both are upper middle class areas with Centerport having some upper class pockets as well, has the best schools in Suffolk county (Harborfields SD); I don't think Greenlawn has a prestige factor but I know Centerport sort of does)
2. Dix Hills/Melville (Half Hollows SD) (both excellent hamlets and great schools; just make sure if you look in Melville that you are within HHH SD as I think there's this one part of Melville that goes to South Huntington SD which is not as good as HHH SD)
3. Cold Spring Harbor/Lloyds Neck/Lloyd Harbor/Laurel Hollow (all considered prestige and great schools although Laurel Hollow is within Nassau County but has a very similar vibe to Cold Spring Harbor besides not having a downtown)
4.Commack (defenitely considered to be an upper middle class area and great schools and besides not having a downtown; everything you need is right there on Jericho Turnpike)
5.Smithtown (also considered to be an upper middle class with a great school district and there's even a small downtown in what's known to be the Village of the Branch but other than that Smithtown is big so there's a lot of shopping)
These are the top 5 best Western Suffolk (and maybe for all of Suffolk County) hamlets/villages in my opinion. Good luck with your move