I agree with everyone's posts. I have been stationed up and down the coast for over 10 years now.
-If you want spectacular views hit up every pull off along the highway each offer something different.
-Lighthouses are wonderful too. Umpqua lighthouse has a museum and tours of the light. Heceta head has a small visitor's center.
-Maritime Museum in Astoria
-Any of the dunes tours
-Cape Arago in Charleston has great views
-Octopus tree and Cape Meares Lighthouse just west of Tillamook
-Tillamook Cheese Factory (squeeky cheese)
-watch boats come in and out of the smallest port in the world @ Depoe Bay
The list goes on and on..... When in doubt stop.
Enjoy!