We just had a gas fireplace insert installed, and used Bassett Home Heating to install it. John, the owner, is a no-nonsense, very helpful and reasonable guy, and runs a nice family business (his son comes along and helps him out). We used them when we installed our gas hot water heater, and he did an OK job.
I was missing a part before the installation, and he was nice enough to stop by the stove place in Lynwood and get the part.
Both times I had to ask and make sure that they caulked where the gas pipe enters the house. But they were much more reasonable than the installers that Rich’s Stove and Spa recommended.
I’d certainly recommend if you need that kind of service in the Seattle area.