Good as they can be, Washington's top restaurants could switch menus and rarely would one notice a difference. Serbian Crown, however, has breathed fresh air into fine dining in Washington. Start with a choice of nearly two dozen vodkas, the bottles encased in ice, the glasses frosty; the vodka marinated in strawberries is like mainlining strawberries.If you can afford it, go on to caviar, a grand presentation, or try a plate full of spicy bits of salad and pate, known as zakuska in Russian, hors d'ocurve in French. The goulash soup is authentically paprika-laced, though sometimes thin. They serve a stroganoff perfumed with the same paprika, as are spicy, grilled, elongtated meatballs. Though the menu is heavy on Yugoslav skewered meats, chicken Kiev, and such Eastern European temptations, the one dish not to miss is the kulebiaka, a pastry wrapped collage of salmon, rice, eggs, capers, and sucn, carved tableside and served with a lobster sauce (I prefer it with hollandaise). It is one of the most delectable dishes in a Washington restaurant. On you could go, to superb spinach tossed with sour cream, and an apple tart of special merit. You can float your meal on a wide choice of wines (at a wide choice of prices) ranging from French to Yugoslav. All this under crystal chandeliers in a rosy stucco and half-timbered room, served by high spirited waitres with the patience to explain the four different raznjicis.