I was considering a generator when Irene came through and we were without power for 4 days. I hated it, I realized how much we rely on electricity.
For many of the reasons 2manytoyz, Greatbear etc said, you should carefully consider the fuel source. I have no gas supply and only a 100 gallon propane tank for the garage heater. So it needed to be gas / diesel. The larger units consume a lot of gas and if they are running low, like in some parts of NH or they cant pump gas.
I chose the Honda EU2000 and the companion so the 2 units can be hooked up to output ~30A at 120v, no 220v.
I bought an interlock for my main fuse panel and a 30A dual breaker and ran 8-2 to a Generac outside 120v 30A box. I tested it after the panel was inspected by the town and never expected to use it in anger.
Over saturday night we lost power and it worked great.
The generators run in parallel, so quiet and nice and easy to carry around. They increase revs when the load increases. We had all the lights available, every outlet, plus I had power in garage. Pellet stove, fridge/freezer, furnace, hot water, coffee maker, dishwasher, TV, internet, no 220v but we have a combination microwave so we used the bread maker and then baked it in the microwave.
Obviously we had to be careful what we switched on at the same time but I did not trip the generators. Each unit holds 1.1 gallons and with low load is rated to run for 9.4hrs.
They worked great, very quiet and know my wife can move these herself.
For us, 2 small units is better than lugging around 1 large unit.
They are also the inverter generator so it is safe for electronics.
We got ours from wisesales.com, very nice to deal with and cheaper than anywhere I could find.
One down side. I was working on a Mini Cooper on my Bendpak 2 post. No 220v to get it down, same thing happened with previous storm.

Luckily we got power back last night so now all set.