The newton, since a weight is a force. However, please note that among the populace, it is common to confuse weight with mass; the correct unit for mass is the kilogram.
grams
Newtons.
pounds
Try grams
kilo-newtons.
ounces
grams
With a scale. Mass equals weight.
Pounds
You would use the metric unit "kilograms" to measure the weight of a bag of groceries.
You would use the unit of measurement called "kilograms" or "pounds" to measure the weight of a car.
You would use the metric unit "kilograms" to measure the weight of a sack of peaches.
You would typically use a unit of weight, such as grams or ounces, to measure a cherry.
oipjigfnj
pounds
Newtons.
grams