We have a generator...a Generax 5500 watt with Briggs and Stratton motor. We live in the semi-boonies northeast of Seattle and we have a 100 gallon saltwater fishtank. If we lose power for very long, we lose the tank (without almost constant manual intervention), and it's a pretty expensive setup. We had a snow and ice storm a couple of years ago and when the power went out we knew it would be a while before we got it back, so Mr. Harlot went out and got us a generator. We've probably used it half a dozen times since then.
When we had our recent windstorm, we were very fortunate to only lose power for 31 hours. Just south of us, some friends of ours were out for a week.
We run extension cords from the generator to the fishtank, fridge, a couple of lamps, the TV
, the DirecTV/Tivo box, the DSL router, our laptops, and a fan to blow across the gas fireplace so we can get heat around the downstairs. Only one area of the house is really comfortable, but it's good enough.