Any campground along the south coast is great, especially if near the ocean. If you can pony up the ferry fare with a TT (as much as around $400-$500 return), a trip to Vancouver Island is a must-do at least once in your life. Many excellent CGs there. The Sunshine Coast is also excellent - one ferry ride but much cheaper fare.
Sunnyside provincial CG at Cultus Lake is nice. Also nice is Brae Island Regional Park next to Fort Langley.
BTW, if going to the Island, I'd go via Tsawwessen and not Horseshoe Bay to avoid Vancouver area traffic. Getting to Tsawwassen from Highway 1 is easy now that they have built the South Fraser Perimeter road.