New York City is like Adult Disneyland. I visit friends there at least twice a month. You can get anything at anytime, and get it delivered it to you. NYC girls are very similar to the girls on Sex and the City. (I can't believe I wrote that, but I found it to be true.) Watch a few episodes, and you'll agree with me.
NYC is a place where everyone is chasing the dollar, everyone is out hustling. But the place has energy. And it really is the greatest city in the world. Unless you become a hermit, you will never be bored.
I don't know much about Cali. But I am almost certain I am going to move there within the next year. (I need a change of scenery, and I too, am sick of the NE's terrible weather.)
For a logical standpoint. Go to NY. When you finish Grad School, you will want to get job, right? You have a much better chance getting a job in the NE. Besides, you won't have to move to the other side of the country, alone. And you can still watch the Yankees.