Thanks for the suggestions. We've narrowed down the sights we definitely want to do. They are as follows:
1. Great Wall - deciding between Mutainyu or Simatai. Will bring the kids for this one but won't be doing the hike.
2. Ming Tombs
3. FC & Beihai then rendezvous with kids/grandparents for dinner at Houhai.
4. Tiananmen & Wangfujing (w/kids)
5. Temple of Heaven & Antiques Market
6. Summer Palace
7. Beijing Zoo & Aquarium
8. Acrobat show at Chaoyang Theater
We still haven't thought about what days to do what or even if we can fit everything in.
What do you guys think?