How many people? How much luggage? AirTrain to Jamaica and then the "E" subway to 50th Street/8th Avenue would get you very close to your destination. The subway will be crowded at that hour, but you would be boarding at the second stop, so you should be able to get a seat. (You also have the option of riding the "E" train one stop in to opposite direction -- to its terminal at Jamaica Center -- and you would certainly get a seat there.) If you only have carry-on size luggage, you can probably slide it under your seat to keep it out of the aisles.
A taxi is always an option, but it will cost about $60 with toll and tip, and might not be any faster than the AirTrain/"E" subway combination at that hour.
How many people? How much