Well, for WA I'd normally suggest the San Juans for moto camping, but I believe you've already done that with an even more appropriate vehicle.
The driveway to our current home is a pretty nice, though short, road, so you should check that out for sure - severs camping spots in the yard if you insist on being outside.
Apart from that - let's see:
Roads in the park around Rainier, and the back way from the gorge to/around St. Helens, Highway 2 across the top of the state, which also leads to the best part of Idaho, 101 is the classic loop around the Olympic Pennisula (which is the prettiest part of the state), and there are
Probably some nice things in the east too. Oh, and WA has the better side of the riding the Columbia Gorge.
101 along the coast has some good bits but it's more scenic ocean road than a great moto road, though if you turn east at Beaver you get to ride my favorite bit of road in Oregon: Nestucca River Road. The Aufderhide Parkway is amazing up the Cascades with Oakridge/Westfir at the southern end - though I understand it was partially closed by a recent rockslide and may not be open for awhile.
...going to have to finish this later - time to get the boy ready for school...
Ok - where were we? Oregon- right:
In the southwest you've got the Rogue Valley with some good roads parallel to I5 between the interstate and Crater Lake, and the bike moving east you can ride theoufh John Day, the Painted Desert and the Blue Mountains on your way to Joseph, the Wallowa Mointains and Hells Canyon.
From there you've got a great road up the Idaho side of the border and lots of pretty roads and trees around St. Maries Idaho.
I'll come back and fix my terrible spelling and add some real highway numbers and such. My phone is not cooperating this morning!