If you are driving down I5 to get from Seattle to Portland, you might want to take a little break in Olympia. There's Bayside Quilting downtown. They're pretty good with a wide selection, but only worth it if you want to have a look at the rest of downtown because they're a bit pricy from having to pay downtown rent.
Or for our better area shop, at exit 102 there's
Ruby Street Quiltworks. They are incredibly nice, and have a great selection of fabrics including some of the Clothworks' American Made solids.