I installed a whole-house generator in my house in Massachusetts. My system produces 16,000 watts and is powered by natural gas; this setup can power my entire house indefinitely.
The generator has an automatic transfer switch which monitors the power that is being provided to the house. During a power failure, the system starts the generator and brings the power on line. It will also switch the house back to utility power when electricity is restored. It is worth not having to drag out a portable generator and fumble with power lines during a storm, only to find the generator to be out of fuel.
I believe a standby generator is even more critical in New Hampshire where a majority of the houses have wells for drinking water. The whole-house system with an automatic transfer switch is the best way to go.