AT ITS BEST, Vietnamese food combines the precise cutting and rapid cooking of Chinese food with the complexity of French seasoning and the visual enticement of Japanese cuisine. There are little surprises of contrast-raw onions and beef stirred into hot soup at the last minute, delicately flavored shrimp paste wrapped around sugar cane, fish sparked with pineapple. And there is the underlying exotic tang of the fermented fish sauce which is the Vietnamese equivalent of soy sauce, and tastes as little like fish as soy sauce tastes like soybeans.

A few years ago Washington and Annapolis had the only two Vietnamese restaurants on the East Coast. Now, Washington has at least ten, four of them in the city proper, and cha-gio, the rice-paper-wrapped cousins to egg rolls, are suddenly recognized as one of the memorable dishes from the Eastern world. For a start, herewith a review of Washington's four in-town restaurants, listed in order of my preference.

Open Monday through Saturday, 10:30 a.m. to 4 p.m. and 6 to 10 p.m. No credit cards.

Cafe de Saigon is the third Vietnamese restaurant in a small hotel called the Christian Inn. And it seems to be giving up. There are fresh flowers on a few tables, but the rose-colored walls are peeling. The plasterwork and fireplace are handsome, the lone waiter valiant, but heir potential charm is dissipated by the second-rate ingredients and the dispirited cooking. The cha gio have little meat amid the vegetables and noodles; the soup is wan, the caramel pork dreary. The fancy coffees - Viennese and such - taste like those instant packaged mixes found in supermarkets. Not everything on the menu is available. And no alcoholic beverages are served. But there is a pleasant beef stew more French than Oriental, and you could easily expect change from a $5 bill after a full meal.