I have had good luck with Champion generators ($300-$400), I think the price for what you get is pretty decent... I have been running a hunt camp off one for 3-4 years and only thing that was wrong with it was the recoil went, Easy fix. We have 2 of them in the 3000-4000watt peak range. One for camp, one for home as a backup for power outages. Now if you have the money a honda looks like a decent one but cost a lot more. I think a EU2000 or somthing similar? I looked them up also and read a lot of good reviews, and hear they're quiet also.

I also looked into propane generators and still think it is a good option, but not many 3-4k wattage like i was looking for, You can however search the net and probably buy a kit to convert it to run off propane, natural gas or gasoline... may be a nice option for different fuel storage. But I do believe a gas generator will be more efficient then the propane one, as far as fuel consumption and running time.

Just my thoughts on them... Hope it helps

Consider your needs first. How much are you planning to run off the genny? Just the freezer or the furnace and a few light bulbs? Then see how much power they draw on the data plate, probably peak and continuous load. Then look for something that will comfortably cover that load.
Gasoline doesn't keep very long, maybe a year. Propane, maybe 10 years or more.
Whole house units are very expensive, over 5K.

They're measured watts, volts x amps = watts. 120 volts x 5 amps = 600watts.

On the subject of using natural gas for your generator. It is a good idea, except if there is a major power outage that that knocks out the local natural gas pumping station. If your going to buy a generator just for emergencies, don’t put gas or oil into it until you need to. Even gasoline with stabilizers in it will eventually go bad, lose their potency and turn into shellac. Rotate your fuel, use what you have in the car and get fresh stuff every other month or sooner.

Not long ago I bought a generator and it was used, when i showed up the guy selling it didnt start it prior and when i tried it would not fire up, Turns out the gas was in it for over a year, so i bought it, took it home and drained gas... Two pulls later and some fresh gas and she fired up beautifully. The guy selling it had no clue that gas went bad... I am surprised at the amount of people that have no idea gas goes bad...

Another good way for finding out your needs as far as size of generator is to build a small extension cord but when you do it split apart the white and black wire inside by cutting off the sheathing, then make a loop in the middle with the black wire and tape it back up. This will allow you to take any clamp on amp meter and clamp on the black looped wire and then plug the cord into the socket and the other end plugs into the item you are testing. I made one thats a total of about a foot long, used it to test the fridge, tv, etc... what ever you want and get a good reading of wattage draw by using the formula 2 posts above. Just an idea some of you may want to try out.