Hi, Gowri Shankar! Recently I used Alpine Specialty Cleaning and had a great experience. They were reasonably priced, polite, quick, and the communication was solid.
Hi Gowri, Airganic is family owned and operated and I have heard good things about them. I also have heard good things about Envirosmart. I don't know how far north they go but I think they would cover North Seattle.
We used Clean Crawls and they were quick and efficient. I asked for before and after pictures and it was so clean after I even went down and explored the crawlspace myself. cleancrawls.com