It may have had its ups and downs over the years, but lately the Tabard Inn seems to be riding a heady crest. The food, in short, has been outstanding, prepared with great care, and, above all, with intelligence. And the service has been a match. Raw materials are fresh and seasonal, and sauces -- even the ones with unusual combinations of ingredients -- are formulated sensibly and applied with restraint. The place is pretty, too, in a simple, neighborhood-restaurant way (although it can be awfully noisy), and there's a lovely garden for warm-weather dining. You won't go wrong with anything on the short menu, but the most interesting dishes are to be found among the daily specials. Look for beautifully prepared fish. There's been top- notch swordfish with a pesto sauce that plays just the right counterpoint, and a delightful thyme-flavored redfish with mushrooms and shallots. Pasta and seafood combinations have been flawless, the pasta firm, the seafood delicate, the sauces neatly tying flavors and textures together. Salads are imaginative, in the New American fashion, but not outlandish, and the unusual appetizers can be smashing -- wonderful prosciutto-stuffed soft-shell crab, for example. The dishes on the regular side of the menu seem less adventuresome; saut,eed chicken breast in mustard sauce, for one, is pleasant but one-dimensional. Don't pass up desserts, generally made with fresh fruits, excellent pastries and the deepest of chocolates. 1739 N St. NW. 833-2668. L $4.25-$8.25, D $12.50-$14.50. L, D daily. MC, V. Res sugg. Full bar.