New York because of those four teams they stand the best chance of a title in the coming years. With Melo they'd have Amare, Melo and likely either Paul or Parker (more likely parker). Then they have nice shooting options in gallinari, rautins, etc.
Still not miami good, but would stand more of a shot than houston/denver/nj depending on what happens next off season. Also NY is obviously the most desirable city to live in of those four options