My first trip I used a shuttle. Took ages.
Last time (DP, me and DD aged 7) we used Dial7 car service.
It was fabulous. We used them four times that trip. (were in NYC twice)
It cost only $10-$20 more than a cab and was great service. I booked online then when you get to the airport you just phone the number and quote your booking. Our driver was waiting nearby and was at the door in 5 minutes. It was great as it was eve of Thanksgiving and the taxi queue was huge. The driver was great and chatted on the way, pointing out landmarks. Car was huge and comfy. Plenty of luggage space.
I highly recommend them. They were very reliable for us.