The most expensive zip codes in America have been revealed, and Suffolk County made it to the number 2 and number 3 slots on the annual Property Shark ranking. But Long Island can lay claim to only the third-place Suffolk. Sagaponack, a perennial power in these rankings, came in at number 3 for 2021, while Boston—which has its own Suffolk County to call home—finished at number two. In the top spot was Atherton, in California’s San Mateo County.