I'm local; I-78 west to the Garden State Parkway, to I-287 (NY Thruway) east to 684 to 84 is the most direct way other than the GW to CBX.
Depending on the time of day, Hartford can be a PITA. If it's raining, or hitting Hartford during either the morning or evening rush hours, the better option believe it or not is when at the Thruway to take it (I-287 west/I-87 north) to the I-90 Mass Pike Extension. More miles but frequently shorter time wise. Yes, traffic in the Northeast can be bad enough that driving another 50 miles can save about an hour.