Yes, we too were looking into a backup generator for our home. We were interested in one that hooked into the natural gas to our home. So there wouldn't be any gasoline issues or outdoor generators getting stolen.
That or propane is the way to go if you're not a mechanical maintenance minded person. Propane is a finite supply, but it also doesn't go away if the natural gas plant is having problems, or your neighborhood's gas service is off due to fire/flooding. We've got a little 8.5 kW natural gas standby generator to install at the new house, came with a lot of other generators from a local generator service contractor. We effectively paid $500 for it, with under 300 hours on it. Bought the lot for the largest generator in it -- a massive 25 kW three phase machine, 3 cylinder industrial diesel, in its own metal shed with a fuel tank in the bottom. That's supposed to be for powering the farm during bad winter storms. For long-term reliability, nothing beats an older all-mechanical diesel, especially military surplus units. Be ready to wrench and do periodic maintenance, though, they're usually not maintenance free units like modern consumer standby generators. We've got a WW2 Army signal corps generator on the farm that still provides good service, a 10 kW unit that starts with a hand crank. It's very reliable as long as you keep the critters out, run it every few months, and don't leave any gasoline setting in it. Thanks, Jonathan