I'm the Bainbridge xpat, and Oregon native.
As long as you are going to Medford go to Ashland
Oregon Shakespeare Festival and see
Crater Lake National Park (U.S. National Park Service). The lake is the remnant of Mt. Mazama, before it exploded (St. Helen type event) it was the tallest mountain in the Cascade Range.
I have no particular favorite Oregon coast motel, we just find a place when we get tired but try to find a room on the beach with an ocean view. I prefer to drive 101 south because it is easy to stop at the overlooks. The views all along are stunning (the road goes inland infrequently). All of Oregon's beaches are public up to the vegetation line, walk them. Sea Lion Caves are worth the stop particularly if you can hear the sea lions bark.. but they are stinky. The coast weather is the reason why our state uniform is a sweat shirt. Be sure to bring a fleece jacket AND a windbreaker. I have one caution, however, our ocean is not a place for swimming. It is cold, there are undertows, and sneaker waves. From time to time a log will wash up on the beach, take care around them because the same ocean that put them there can pin you under them. Along the same line stay behind safety fences and do not try to climb sea cliffs. We like our visitors to make return trips.
http://www.oregoncoasttravel.net/ Hgy 101, 'mile-by-mile'
Oregon State has a marine science center at Newport. The center and the town are worth exploring.
Oregon Coast Aquarium - Newport
Cannon Beach is a very popular town, you will see lots of tourists and locals.
Seaside was the town the teens would go to in my youth to cut-up, little has changed. It is only an hour's drive from Portland.
I see you have friends in Portland metro, if they take you to Washington Park via Park Place give me a wave, maybe stop for a glass of wine.
A must-take drive is up the Columbia River Gorge to Hood River (take the scenic route if you have time, do not miss Multnomah Falls
http://www.oregon.com/attractions/multnomah_falls), then south around Mt. Hood, dinner at Timberline Lodge (a reservation is wise, or call from your cellphone about an hour out for a table). The Lodge is well worth an overnight stay.
Timberline Lodge Skyvue was referring to the fish hattchery at Bonneville Dam.
http://www.nwp.usace.army.mil/op/b/home.asp which is on this route.
I have mixed feelings about stopping at Mt. St. Helens. I am not sure that the visitor's center is still open and, frankly, nature has done a great job reforesting the mountain.
Seattle: Washington State Ferries provide the best cruising value going, $6.90 RT for Bainbridge or Bremerton foot passengers. If you are 65 or older buy your ticket at the ticket office and be sure to ask for the senior discount (half price).
http://www.wsdot.wa.gov/ferries/ The Bainbridge run takes 35 minutes each way, departs roughly 45 minute intervals. If you take that trip walk up the hill and take the path mid-way to the left, the "Walk Around". My favorite watering hole was Doc's,
Doc's Marina Grill. If you just want to watch the scenery take the Bremerton run, it takes about an hour each way. When you pass the fish farm in Rich Passage look up the hill closely to see my former home. The photo to the left was taken from my study.
At Seattle Center
Seattle Center - Create your Seattle Center Experience! you will find the Space Needle and adjacent The Experience Music Project
Experience Music Project|Science Fiction Museum and Ride The Ducks Tour
Ride the Ducks of Seattle - 206-441-DUCK.
I enjoy
Seattle Art Museum: Home Page , they have a branch Asian Art Museum that is great.
Ivars is the local seafood restaurant chain, but
THE seafood restaurant is Ivars Salmon House on Lake Union
Ivar's Seafood - Seattle's Best Seafood and Chowder
I could keep going, and going...