(lives in Seattle)
Fanatik is a solid [HTML_REMOVED] worth the trip. Probably other great shops up north too.
Locally I'd hit Big Tree bikes, or maybe Gerks (Issaquah).
To be honest, there's not currently a local shop that really excites me, although there are a few I do really like for random things (namely big tree and recycled cycles).
I checked out river city cycles in portland recently, that was impressive. Drool-worthy selection, from low to top end, and low key sales people that knew their shit.. and no sales tax.