Three of my children (15,21,21) and I went on the afternoon LA and Hollywood tour with Bing, and were so very pleased that we had made this choice. The children had never been to LA, and the tour gave them an overview of the city with quite a few stops to take in some areas better - and all in just over 4 hours.
Bing's commentary was excellent too. We all learned a lot. For us, highlights were Griffith Park and the drive through the Hollywood and Beverly Hills. We highly recommend Guideline. Even if you have a week in LA, you might want to start with this tour so you can plan where you want to spend the rest of your time better.