Well I can only speak for CA, below San Francisco, you would want to switch over to HWY1 which is scenic, below San Fran, 101 continues inland through Silicon Valley, nothing special to see the rest of the way down, Hwy 1 takes you along the coast. Slower for sure, but ocean views most of the way.
Hwy 1 will take you through Half Moon Bay, stop for lunch at Sam's right along the coast, lobster sandwich and chowder is killer! Santa Cruz..keep on driving, leftard breeding ground, but there is the Municipal Wharf and Boardwalk.. through Montery you have a nice aquarium and lunch on Fisherman's Wharf, Hearst Castle along the way further south, spectacular views through Big Sur.
Yes CA hwy 1 is a must see.
Have seen probably 90% of the coast from Mexico to the the NW tip of Washington, have rode from Crescent City CA. to Long Beach WA. and beyond on a motorcycle.
I would probably go west at Longview WA, cross the bridge into Astoria OR. and then south.
