Whats the best way to get from Philadelphia to New Haven, through New york?

By train there are two alternatives: 1) AMTRAK direct, either the Metroliner or Acela trains from 30th Street station lower level, or 2) local trains - SEPTA route R7 from Center City stations to Trenton, change there (a short walk along the same platform) to the NJT train to New York, then another change to the NewHaven train. Journey time is only about 40 minutes longer than by Amtrak, but half the price. Bus travel is more cramped than by train, and the passenger is confined to their seat. Once on board a bus, luggage is not accessible, being stowed underneath the floor, whereas on a train the passenger may access luggage at any time. On a train each pair of coaches has its own conductor, whereas on a bus there is only the driver. Safety is greater on a train than on a bus -road accidents involving buses are much more frequent than train accidents. However, fares by bus are usually cheaper than rail.

I don't know. Try mapquest.com I use this all the time