Can't speak highly enough of the Seattle Pinball Museum (SPM). We visited there in mid 2015, so I assume it may have changed in the interim (some pics & thoughts on SPM here -> http://www.ausretrogamer.com/flippin-fun-at-the-seattle-pinball-museum/ ).
The other one was Shorty's - loved the pinball tables they use in their booths and of course, their machines to play out back.
Can't wait to visit Seattle again.