The following doctors are used by us and other people in Seattle and recommended by friends and people on the web. They provide health report for green card (I-485) application.
Dr. Jiegang Y Zhou
Rainier Occupational Medical Center
1400 South Jackson Street, Suite 24, Seattle, WA 98144, (206) 568-8577
Comment: very nice doctor, price is around $175 (including lab for tb), in Seattle International District.
Dr. Kenneth Hong, M.D.
623 South Weller St, Seattle, WA 98104, (206) 621-9919
Comment: good service and affordable pricing, in Seattle International District.
Dr. Pen Hou
Redmond Family Care
8195 166th Avenue NE, Suite 203, Redmond, WA 98052, (425) 310-6519
Comment: used and referred by some folks on the web.
Dr. Liqun Zhu
Evergreen Primary Care Center Redmond
8980 161st Ave NE, Suite 400, Redmond, WA 98052, (425) 899-2273
Comment: originally from Shanghai and in her 50s, she is very nice and listed on the civil surgeons list.
Dr. Daniel V. Phan
6508 196th St. SW, Lynnwood,WA 98036, (425) 673-2572
Comment: seems to be a Vietnamese, easy to make appointment (second day or same day for example), pricing is not expensive. He could do immunization shots as well as X-ray. For example, if your immigration TB skin test doesn't pass, you could do X-ray there rather than going to another clinic. Their X-ray is cheaper also.
More doctors providing immigration medical exam services, please see this list on USCIS website:
Civil Surgeons in Washington