Surprised no one has mentioned Li Qun. This restaurant is in a hutong neighborhood, and looks ancient, even though the restaurant itself is only 17 years old. Opened by the former head chef of Quanjude, the place has quite a reputation as a lot of famous celebrities and dignitaries have visited, as shown by the photos on the wall, despite the "run-down" atmosphere of the place.
Compared to Quanjude, I have to say the duck "looks" not very pretty at all. The ducks look anemic, and the skin rather saggy, not the fat, shiny, beautiful duck that you expect. Taste-wise, it's very good. Not too oily, and the skin sliced how it should be sliced.
The restaurant itself is pretty bad. I've eaten in a lot of dumps, but this one nearly takes the cake. Forget about the toilet. If you need to drop the kids off at the pool, you're s*** out of luck. If you see the toilet, you would rather soil your pants than take them off, even after you have puked all over yourself. Definitely not a place to take a date or the kids.
Despite the quality of the duck, still, compared to Quanjude, which was a bit more oily, I liked Quanjude better.
I also went to Da Dong on my latest trip. This was the best of all.
I hereby proclaim Da Dong the best Peking Duck restaurant in Beijing!
First off, the restaurant itself is gorgeous. There are at least two Da Dong restaurants in Beijing, and I don't know the English address, but the Chinese address as sent to me is: 大董北京烤鸭店，北京东城区东四十条甲22号南新仓国际大厦1-2楼(东四十条桥西南), Tel: 86 10 51690329. This is the one I'm recommending.
The atmosphere of this place is incredible. Just a beautiful, classy restaurant with a lot of atmosphere. We had ten people and our server had politely reserved a private room for us upstairs, but I would have preferred the main downstairs dining room as the atmosphere is much better. Unfortunately, they were fully booked so we couldn't change the table. If you go, I would definitely make a reservation in advance.
Beside duck, they had a lot of other incredible Peking-style dishes, and the best was it came with an English menu with lots of photos. In fact, nearly every dish had a photo so it was easy to know what you're ordering.
But the duck, it was fantastic! Not greasy at all, it looked gorgeous and tasted better than the other two famous Peking Duck restaurants we went to. They also provided a lot more condiments, with two types of hoisin sauce, sugar, green onions, cucumbers, and some kind of pickle, and they provided the thin flour pancakes as well as a type of hollowed bread. Delicious.
After we finished the duck, they brought a duck soup made from the carcass of the duck. Awesome!