Actually Samsung has a good policy about this. You are only allowed one free meal of choice. The food is preportioned but good quantity that it will be sufficient for anyone. But you don't have a choice of throwing away your first choice and going for second.
the food at samsung is 50% off for employees, they have Indian, BBQ Korean, Salad, Italian, Pizza, burger, Sandwich , Sushi, Juice stations which are pretty good... Free coffee ... you spend around 3 $ for typical lunch but not free..