I live in Nassau Co. also and I have 4 cellphones. My daughter and I are on Verizon family plan. My wife just switched from ATT to Verizon under a separate account. My son still has ATT (an old east coast plan) which I will keep for another year and then I expect he will switch carriers unless GSM has better coverage.
Verizon family plan is not really that great. If you do the math, you don't save any money if you add the $20/phone and the difference in cost to move up to the next level of minutes. It is just convenience of paying one bill and sharing the minutes.
But beware, if you do any changes to one plan or phone in a family share plan, you are renewing the contract for 2 years for all in that plan. Based on that I suggest Verizon wireless but not as a family plan, unless they lower their prices to add family members to that plan.
i am a resident of nassau county, new york,i have 5 members on att shared plan. any info on whats best shared plan for 5 phones