If you're going to be in WA, I highly recommend Olympic National Park's beach camping. You camp right on the beach - it's fantastic! If you're into more "developed" camping (as in, actual camp sites to pitch a tent) then the Kalaloch campground is fantastic. If you're more adventurous, there are many walk-in campsites right on the beach. You have to carry your own gear (including water) though, but it is much more quiet and relaxing. There are quite a few sites that are right off of the trailhead (and road and parking) so you don't have to walk too far with your stuff, but it does give you a more isolated feeling. I love wilderness camping!