If it's Ninoy Aquino Airport terminal 3, walk out the front door, across the car parks, across the main road, down the soi on the left of the Sheriton, turn right and there you have the Newport Mall which has plenty of shops, restaurants and coffee shops along with a casino. English movie complex as well. About 1/2 Km walk. Also a few fast food joints on the way.
I always go there if waiting for a flight.