Harbor Freight Predator 4400
It's my favorite only because it's the one I own. 4400 Watt starting, 3500 Watt continuous and 120V only.
I added natural gas capability with a few eBay/Amazon parts.
Hot water, furnace, clothes dryer, oven, range are all gas so the house has no 220 loads and little total load.
The panel has a lockout and a backfeed breaker. The adapter cable feeds L1 and L2 in phase which works fine in this situation.
Furnace blower starts up fine while the double boiler espresso machine is heating so it's good enough.
It ran about 3 hours a couple days ago. I've got freezing rain as I type so we'll see if I start it up again tonight.