If you are really into glass a visit to The Museum of Glass in Tacoma is worth a visit. They have a hot shop where you can watch glass being blown and guest artists from around the world visit, lecture, and blow glass. http://museumofglass.org/ There is Chihuly glass there and in the Tacoma...
+1 for Butchart.
Victoria has a good Maritime Museum, but amazingly there is no one definitive maritime museum in the Puget Sound area that I know of. Seattle has MOHAI (Museum of History and Industry) http://www.mohai.org/. Tacoma WA has the Foss Waterway Seaport...