Royal Banquet - restaurant called by many names, but chef was the state cook when Nixon came to town. Amazing meal (been 3x!). Heard it has gotten popular and expensive though.
Great Wall (Badaling is closest) is a must see. I enjoyed the ride to and from almost as much. You can hire a private driver with a car and a cooler of ice water for about $40 a day IIRC.
Beijing has changed so much in the last five years. In my last trip I've never seen so many new cars. People are making the jump from bicycles to cars.
One fun fact: Notice that ALL the trucks are blue.
You've been to Shanghai, so notice how the food is great, but different. The #17 is particularly good.
Have a great time!