Residential Market Analysis
Lynnwood, WA 98036
Phone: 425-670-8237
Unfortunately, they do not have a web site but they have very good information (including address and rent income). Many companies use this as a source for residential information. Fax request and delivery service.

Home Rentals
Tacoma, WA 98464
Phone: 253-566-0383

Homes & Condo's For Rent
Kent, WA 98031
Phone: 253-850-6133
Contact: Dupree and Scott

HomeStore
Home to Spring Street and All apartments. Consumer focused site.

MacPhersons / Prudential
Property management company

Rent.net
This site is mainly consumer focused and has average quality information.

Relocation Central
Mainly consumer focused

Relocation Central / Apartment
Listing of several buildings along with their rent, size and bedroom count
http://www.relocationcentral.com/directory/us/wa/seattle/apartments

Seattle Apartment Insider
This site is consumer focused with good statistics and information

Rent Check
A resource for finding rental property information on the Internet. Information includes address and price

Seattle Times
Classified ads, some with addresses

Windermere Real Estate - Rental Info
http://www.windermere.com/index.cfm?fuseaction=Listing.SearchPropertyAddress&ptyp=6

COMMERCIAL INFORMATION

OfficeSpace.com
CoStar.com
CommercialMLS.com