Many good spots mentioned - Full Tilt Ballard's machines are kept up in EXCELLENT condition, by the way, and nice lineup... BDK, CFTBL, FT, IM, J*B, LOTR, MM, TSPP, SP, TRON, Taxi, W?D, WOZ. No one has mentioned John John's or The Unicorn (Narwhal), two good places on Capital Hill. Add-A-Ball is wonderful as well and has a great modern/classic mix.
Seattle is a GOLD mine for pinball on location Use pinballmap.com/seattle and look up the locations given to you in the thread, as well as others