Not sure what you mean by "best." There is express bus service from JFK to Grand Central Terminal -- a short walk from the Roosevelt -- that costs about $15/person, I believe. Or if you spend $13.60 on a Metrocard, you will end up with a card worth $14.50 (after the 7% bonus for purchases of $10 or more); that will cover the cost of the AirTtain to Jamaica Station, and the subway for two people. You can take a Manhattan-bound "E" subway from Jamaica Station to Fifth Avenue and 53rd Street. If you exit to the rear of the train, you will be at Madison Avenue and 53rd Street -- about a ten-minute walk down Madison to the Roosevelt.
Not sure what you mean by