This is a big question with many answers and variables. Apart from parents with violence/drug/drink issues then surely the best person to look after the kids are the parents themselves with support if possible from the grandparents. A lot of grandparents these days are a little out of touch with the younger ones especially the ones that drink, smoke, moan a lot and aren't very active, so not the best choice as role models or to be constantly keeping up with active children that want to do a million things at once. I have friends whose parents are wonderful grandparents and very active (Bungee jumping, gym, parachuting, clubbing) and the kids who are teenagers and their friends can't seem to get enough of them! maybe the bottom line is different circumstances requires different and fluid parenting/grandparenting and at the end of the day as long as there is a lot of love there that's the main thing but a child getting brought up by grandparents usually points to a reason which is usually a bad one, parents overworking, violence, substance/sexual abuse, mental illness or just not caring.