It has been a couple of years since Mrs Bond and I were there, but here are the highlights we enjoyed -
Pike Place Market - including having a coffee in the very first Starbucks - if you have time, book a foodie tour of the market.
Take a walk around here - http://www.chihulygardenandglass.com/
Then head over to the Space Needle which is a stones throw away from Chihuly Garden
I'm sure there will be more suggestions, but hope this gets you started