I don't think I could deal with the issues of storing fuel and avoiding gunking up a generator that would sit unused for years at a time. I've just waited out power failures and decided not to get serious about buying a generator. Yeah the stuff in the fridge can go bad if the power is out for too long, but spending $1000 on a generator to rescue 20 bucks of perishibles isn't financially sound. During the east coast blackout last year, people had outdoor barbecues and gave away food so it wouldn't spoil, and it was very relaxed and friendly, nothing like how people imagine NYC.

I could see having a small 12vdc to 120vac inverter to do stuff like charge up portable batteries in the car. You can get a 15 minute NiMH charger with four 2500 mAH AA cells for $25 or so now (Eveready), good for flashlights, radios, etc. It's really not necessary to run all the lights in the house when the power is out. Just have a few LED lanterns and flashlights around, use daylight for doing stuff and sleep at night.