I have a Yamaha EF2400ISHC inverter gen-very, quiet, reliable and fuel efficient. It can power up important elements in the house (gas furnace on a dedicated single static switch in winter or a window a/c in the summer) plus things like the sump pump, refrigerators and utility use. I keep 20 gallons of gas in safety cans typically, and am just about to install a propane kit to make it dual fuel.
I had a much larger generator with the idea I'd get it hooked up to my house electric ($$), but the issue with those is that you have to feed it. If you have natural gas, great, but you might have to spend more $$ to upgrade your line (etc.), get the kit ($) and if not, then you gotta find get large propane tanks and get that kit ($$) or start hauling gas as that generator would go through a several gallon tank just a few hours in (pain).
So, I went smaller (and portable). The twenty gallons of gas is enough to keep going for the better part of ten days or so alone I figure, more if used intermittently. That will get us by.