Our family is visiting Williamsburg, VA this summer..and have a question!?

My husband and I are traveling with our two young children, in the age of 10 and 9 to VA this summer. We are staying only couple of days in Williamsburg, then off to Virginia Beach and other towns. Now, my question is out of these three very famous tourist attraction sites in Williamsburg, which is Busch garden, Colonial Williamsburg and Watercountry USA, we want to just choose two. We can't afford to visit all three, and don't have enough time for them. So for those who's already visited VA, what two places would you recommend for us? I really appreciate your help! :)