So Cal Bleg

For the past seven summers (!), we've done one week in San Jose with my parents and one week with Amy's parents either in Ocean City or the Poconos.  But the kids are old enough to do something different now, so what we're going to do is fly out to California for two weeks, and spend half of that time up north with my family and the other half down south seeing friends and family and seeing the sights.

Which brings me to my bleg.  I know So Cal reasonably well, so I'm not a complete stranger to what's all out there to do.  But I welcome your thoughts and suggestions on where would be fun for an 8 and a 6 to go.  We're pretty open so fire away!