Crystal Cove State Beach campground is located within a 10min walk to the beach.  Unfortunately you have to go under the busy/noisy Pacific Coast Highway to get there. There's a great historic area that's worth checking out. There are a variety of campsite throughout the park from RV to tent; all of them have great views. There's also an abundance of hiking trails.  

I only gave it 4 stars due to cost and the noise from PCH

Cell Coverage: Excellent

Cost: $55 - $75