Lasting Memories in Lynnwood, WA is the best scrapbook store around. It's about 20 miles North of Seattle, just off I-5. Well worth the trip!
If you enjoy A Muse stamps, A Muse Artstamps is located in the Greenwood neighborhood of Seattle:
http://www.amuseartstamps.com/
Of course Impress is also a nice place to check out. They have a location in the Bellevue Square mall, University Village in the University District, and Southcenter in Tukwila (near the airport). Southcenter is their largest location.
Enjoy your visit! It's been chilly (well, for here anyway).