I use Animal Medical Center in Manhattan... you can use them as your regular vet or just go to see the specialists. They are very, very expensive so I will sometimes go elsewhere for minor things, shots, etc. But they are well worth the money otherwise. They take a lot of time with you, will spend as much time as necessary talking to you, they make multiple follow up calls because they truly want your pet to get better. They also do not do unnecessary things, they will go slowly through tests one by one, starting with the least invasive ones first.
It is also nice that they always have specialists there... for example, a few weeks ago I took Chloe in to the general practice because she was limping... well the vet decided to take her over and have an orthopedic vet look at her as well, so I basically got a free ortho consult.
Here is the link:
Animal Medical Center - New York City