I'm not sure you get the total picture of success until your children are grown, with children of their own. But, I think you can get a really good idea by your childrens actions along the way.
I doubt that my ideas of what it takes to be a great parent (good isn't enough for me) are the same as the majority of other parents out there.
I say that because not many parents are parenting the same way we do.
I know what it takes in my opinion to be a bad parent, so I've done everything in my power not to be one.(I learned from my own parents mistakes)
I've always put my childrens needs before my own, which I think goes a long way. I've always made a point to be there for my children. I've made myself available to offer my knowledge and wisdom throughout the years. I've put myself in a position to be a positive role model, I don't do anything that I've told my children not to do.
Children learn what they live.
I still have a few years to find out just how successful I hope I've been, but if the past and present actions of our children are any indication then we've been doing things right.