Most of the restaurants in Chinatown look seedy, no matter how good the food might be. In the past, I've recommended Full Kee, which was exceptional and a favorite of some of the best chefs around town, who would stop there for a bite after their own restaurants had closed for the night. As I write this, Full Kee is undergoing a renovation, but it will have re-opened by the time you read this. Let's hope that its appearance has improved but that its food has remained the same. So, check it out, if you like: Full Kee is located at 509 H St. (tel. 202/371-2233). But back to Tony Cheng's: this is the most presentable of Chinatown's eateries, and also a good choice if you like Cantonese specialties and spicy Szechuan and Hunan cuisine. The restaurant has been here for 27 years and has earned a reputation for its Cantonese roast duck (see it for yourself before ordering, since it is displayed in a case at the back of the restaurant); lobster or Dungeness crab, stir-fried and served with either ginger and scallions or black bean sauce; or Szechuan crispy beef, to name just a few.