Just came back from a ~3000 mile, California, Oregon, Idaho & Washington trip on my dad's GS.
Bottom line up front: HYW 1 from Rockport (south of Lost Coast) to Bodega Bay is the best road. Great views, twisty, not a lot of traffic or gravel, not a lot of towns where you have to slow. Oregon Coast is not that great.
North on 5 to 44 to Lassen Volcanic National Park (89 still had sections snowed in)
89 North
229 North East
395 North
31 North West (Stopped at Paisley Saloon)
Camped at Summer Lake Hot Springs
Crater Lake
97 North Through Bend
20 to 22 (good part)
NF-46 to 224 (best part of first 2 days)
Stayed in Portland
Met up with a friend and my cousin and did this for 4 days:
https://www.google.com/maps/d/edit?mid=1p-uFGTB6OY0yuo8Yni6soLy0BcM
Into Washington to ride the Colombia Gorge and back to Portland
Highway 8 and 6 to the Oregon coast
South on 101 (coastal highway in Oregon)
South of the Lost Coast HYW 1 to Bodega Bay
Home to Campbell
About 8 days
Devils Canyon Idaho
Painted Hills, OR
Summer Lake Hot Springs, OR
Goose Lake, OR
Lassen, CA