Going to Seatle for 10 days on some R&R.

Any suggestions on what to do and see?

The Space Needle and Seattle Center are a must, the Aquarium's pretty good, catch a Mariner's game at Safeco if you're a sport fan. I'd rent a car and take a ferry out to the San Juans for a day or two, we've got big ferries- you can take your car on them, Deception Pass at the north end of Whidbey Island is my personal favorite. Or drive up to Vancouver and head over to Victoria if you've got the time. I haven't been to the Experience Music Project, but I've heard it's worth the price of admission.

at the most seven days in your city. I was there years ago in the early eighties with my wife and kids and remember having a good time, but we were kind of restricted (with kids) on what we could do. No kids this time. Thanks for the info so far.

It could be my imagination, or just dementia, but it seems like Seattle's changed quite a bit since the early eighties. For better or worse I can't decide.

If it were me and I was spending several days in the area, with no kids, I'd rent a car and spend our time staying in B&B's up and down the Sound. I especially like the Bellingham area. Oh, and you've missed the Skagit County Tulip Festival but they may still be in bloom. Those fields are something to see.

below the market.

You should give Seattle DUers a shout in the Washington forum when it's close to time for you to come up here!

SOmeone mentioned the San Juan Islands, Vancouver, and Victoria. All make great side trips. Check out the Amtrak site for some specials on fares and accommodations.
You might want to check out the Washington shore too.
Some National Parks in the area include Olympic National Park, over on the Olympic Peninsula, and Mount Rainier. Be prepared to see a lot of snow still in both places.

Mt. Rainier. I just did a report on it.

A beautiful drive (I used to manage an office there, and went out there once a month). There is a ferry from Pt. Angeles directly to Victoria, which in my opinion is definitely a must-see destination.

to the south.
Some museums opened up down there in the last four years or so. One is devoted to glass and you can see the process of glassblowing as well as see exhibits.
Tacoma has an art museum and a historical museum also. Seattle's Art Museum is closed for renovations but the Seattle Asian Art Museum is open.
Are you traveling with kids? Both Seattle and Tacoma have good zoos and Aquariums.
Another thing I forgot -- Tillicum Village. You catch a boat from the Seattle waterfront to the small island and see a show on Northwest Native American culture. They also serve a salmon meal with it. It may sound hokey but my visiting friend and I really enjoyed it.

And I second SeattleGirl's suggestion of the Pike Place Market. Ride the monorail for a look at Seattle from above the streets.

There was an accident last year and it has not run since.

The two trains sideswiped each other a few months ago, and they said it would take quite some time to repair them, which is too bad, because it is a nice little ride.

Riding it was a little on the scary side.

the narrowest part of the route, which is not supposed to happen. The scraped sides, and then stopped. It was a bit scary, as there were people on the trains when it happened. It was quite the job to get the trains apart again.

My b/f grew up in Bellevue... the Snoqualmie falls was one of the first places he took me!

think they just opened Johnson Ridge again (rip johnson)

It's a fabulous area to visit! Just make sure you have good brakes on the vehicle for the drive back down the mountain!

You could stop in Tacoma to see the Chilhuly Glass Museum on the way to or from. If you go to Victoria, take time to go to the kitschy Bushart Gardens, with its ever-changing displays of flowers. Vancouver is worth several days, especially if you have never been there. It is a very walkable city with great parks (can't miss Stanley Park, great restaurants and more visible ethnic communities than Seattle. The museums are also wonderful. The Provincial Museum in Vic. is a can't miss.
Back to Seattle, visit the Hiram Chittenden Locks with the fish ladders, watch the sailboat races on Tues. nites from Gas Works Park.
If you have the time, go to Pt. Townsend on the Olympic Peninsula and then drive over to Sequim where the walk on the sandspit (Dungeness) is fantastic with wild water on one side and calm on the other. You could consider going to Winthrop now that the pass on Hwy. 20 is open--a bit of the wild, gentrified west.
Or you can simply vegetate in one of our famous coffee shops!

lots of wooden boats and uppitypeople here. Peaceful town, sort of like being in a big train set (Main Street building association restrictions). Wooden boats and other boats. Old hippies, young hippies, uppity people "we're all here because we're not all there". Lots of B&Bs in victorian homes. Did I mention boats?

Oh, and check out Walter Kelley on the Fox Morning Show. Yes, I know it's Fox, but he's my brother-in-law and he's a sweetheart.

The local one here in Oakland is one of the best in the Bay area as far as the news.

http://www.henryart.org/

then enjoy the University District for half a day.

Eat breakfast or see a show at the Crocodile Cafe.

http://www.thecrocodile.com/

then barhop around Belltown.

Capitol Hill is often still fun, with much to recommend it.

Fremont is pretty boring any more.

The Ballard neighborhood has many pockets of charm.

Go ahead and go up in the Space Needle. It's really 60s Futurist.

Cyclops is another good joint down in Belltown.

I usually have a steak at the Alibi Room at the Pike Place Market.

Seattle Art Museum is (thankfully) closed until next Spring.

Go take a slow, eyes-open tour of every floor in the main Seattle Public Library, the one designed by Rem Koolhaas. Read debate about the advisability of this course of action here:

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=105&topic_id=3721459

See this site:

http://www.thestranger.com

or pick up a copy of the Stranger or the Weekly for free on the street to decide what to do.

if you like baseball.

Walk around the island, see what's happening that night (maybe some music on the island), eat breakfast, take the ferry back.

fairly inexpensive for walk-on passengers, nice boat ride across Puget Sound and back.

The Red Hook Brewery is in Woodinville, as is the Chateau St. Michelle winery and the Columbia winery. There are other small wineries, but I don't think they have visitor facilities.
The biggest darn plant nursery/greenhouse you've ever seen is also there. (http://www.molbaks.com/)Worth a look if you're in the area.