Where is a good place to meet someone in the Amsterdam airport. We are arriving from 2 different countries (USA and S. Africa).
Is Amsterdam your final destination? If so, right after you collect your bags you will be at the Schiphol Plaza - which is like a shopping area / train + bus station.
This plaza is a vast courtyard and contains many shops, the main ticket station for the rail systems; the kiosks where you can buy transit tickets, the entrances to the trains (escalators going down to the basement) and where the official meeting point (white and red painted building) is located.
It is hard to miss as you naturally end up in this area (if you are not being picked up by transportation); of course you are free to pick any place to meet here - the official meeting point stands out from the crowd, but you can pick another reference point; such as the train ticket counters.
If you are both transiting in Schiphol and are looking to meet airside; the easiest place is this Mediterranean Sandwich Bar; it is recognizable by the large green metalwork/decor. It is located at the escalators that lead up to Lounge 1, next to a yellow information booth, a Starbucks and the flight information displays. You can't miss it since it is one of the unique looking shops in the airport (the others all kind of blend into the decor).
This 360 panorama gives a better idea of the location of the store.