Steve and I lived in Seattle for 6 years, leaving for England in 2007. Here is a running list of reccomendations that we make to friends who are going to be visiting there.
Bloedel Reserve: A fabulous garden on Bainbridge island. Note that you are required to book your visit in advance. http://www.bloedelreserve.org/
Ride the ferry: A good, relatively inexpensive activity is to ride the Washington State Ferry. On foot to Bainbridge and back is nice for a few hours. If you want to take your car and make a loop for a day trip that is also nice. http://www.swdot.wa.gov/ferries/
A former co-worker has a food blog with good reviews and reccomendations. Good resource for foodie types. http://www.tastingmenu.com/restaurants/seattle/
Our favorites: (where we liked to eat)
Mediterranean Kitchen: Lebanese food. Garlicky and oh-so-yummy. Our very favorite in Seattle.
El Gaucho: High-end steak ($75+ per person)
The Keg: Solid steak place
The Pumphouse: Our local restaurant when we lived in Bellevue. The closest thing to a proper English pub that I know of on the Eastside. Basic American pub food.
Qdoba: Lunchtime burrito fix (food coma likely afterwards)
Seafood and sushi:
*Note: Steve and I have some seafood allergies, so this is not our best subject. Seattle has a very large east Asian (Oriental) population so those cuisines are generally very strong.
Elliot’s on the Seattle waterfront is excellent. On weekday afternoons they have an oyster happy hour where they start really cheap about 3pm and go up in price until dinner time. If you like oysters it is a must do. Also good dinner menu. On the pricey side. http://www.elliotsoysterhouse.com/
Nishino is a very highly regarded Japanese seafood restaurant. http://www.nishinorestaurant.com/
Our church in Bellevue http://www.cbccross.net/