There are more than one around the city, but I usually take http://www.nycairporter.com http://www.nycairporter.com to get to/from JFK/LGA and Manhattan when I

There are more than one around the city, but I usually take http://www.nycairporter.com http://www.nycairporter.com to get to/from JFK/LGA and Manhattan when I don't want to take public transit (usually because I have a lot of luggage). I live within easy access of one of their pickup/dropoff stops in Manhattan, so it's quite convenient.