Visit any nice restaurant in New York and you’ll see a fair percentage of the people drinking tap water. Ignore them. Either they are trying to prove to their companions (or the other diners) that they rich or they simply don’t know that New York’s tap water is far better than most bottled waters. It regularly wins competitions for best municipal water in this country, though it did finish a terrible second in one recent competition.
I’d actually go a step further and advise visitors on a budget to choose New York’s tap water over wine, beer or any other beverage that costs money. I say this not because our tap water is so good that it tastes like wine or beer but because of relative value. New York has some of the world’s best food, food that’s better than anything you’ll find back home, no matter where home is. But it sells the same beverages you can wherever you live and wherever else you travel — only the restaurants here charge way higher than normal prices for those very standard beverages.
If you have a limited amount to spend eating out while you’re here, you should devote all that money to purchasing food you cannot buy elsewhere rather than beverages you can buy anywhere for less.