I recently stayed at the new JFK Marriott--it is fantastic! Wonderful, friendly staff! Superb M Club, with amazing views of JFK and even an outdoor terrace! And, to top it off, you can order from the full dinner menu from the restaurant if you want, in addition to the offerings provided in the lounge. Only M Club I've ever seen that offers this benefit! Highly recommended! I will be back many times!

(Also: 24/7 gym, and if you prefer to exercise outdoors, there is a wonderful, huge city park just up the street with a lake and lots of open green space)