Many factors determine which water heater is best for your home.
The main factors to consider in choosing your water heater are:
The budget is very important since you cannot bring the water heater home without money. Two thing to consider, high investment, low operational cost or, low investment but high operational cost, the best is low investment, low operational cost.
The space is determined your capability to install big water heater like solar water heater, or tankless water heater.
Infrastructure is determined you can buy big one for all or must install in every place due to no hot water piping ready.
The next step are calculate the needs.
one person need about 20-30 liter hot water for one shower
if you have 20 liter tanks and take shower twice a day then your water heater should be able to heat the water within less than 10 hours for 20 liter.
if you need to take bath then you may need more hot water, please calculate wisely to save the investment cost and operational cost without losing your comfort.
A good sales of water heater should be able to help you to calculate your needs, if they cannot, are you sure, you got the best ?