Net Worth is equal to assets minus liabilities. Which event will have the greatest impact (positive or negative) on one's net worth?

I would say that buying a house or apartment will in most people's cases have the greatest impact on the person's net worth. If it is bought in a big city like Vancouver it is highly likely that it will appreciate in value. At first it will be a iiability but after a few years if the marked is good then the value will go up so the equity of the homeowner will increase thus increasing net worth.