I'm partial to San Diego having lived there for five years as there is a lot to do and it's the least similar to what you described in the second sentence of your intro... Legoland would be fun for your boys and it's not bad for the parents either. San Diego Zoo (both of them), Midway museum, and I would also recommend an overnight trip to Catalina on the ferry, because often that ferry ride can take the place of a separate whale/dolphin watching tour. Or, if you're into crowds rather than serenity, you can visit museums, beaches, parks, etc., rather than Catalina.
Or, an alternative trip could be fly into San Fran, spend a night/day exploring, then hop in a rental and head south on PCH along Big Sur. Spend a night or two in Monterrey, Santa Barbara, etc., whatever strikes your fancy while planning. Last day get into LA, explore Newport Beach, Venice Beach, etc. and fly out next day. I thought Hollywood was super boring but enjoyed visiting each of the beach communities because there are different vibes.