SOHO. With a menu almost exclusively devoted to seafood, Aquagrill is an excellent pick for diners who want great choice and unparalleled options. Try lobster or salmon prepared to your specifications, or come early, eat oysters and people-watch. No matter what you do, save room for a perfectly prepared dessert. Locals also rave about Aquagrill's brunches, and single diners can get a great meal at the bar. Reservations recommended. Dressy casual attire. TRAIN: C, E to Spring St

MIDTOWN EAST. Ever wanted to dine like the Rockefellers? Aquavit, which is located in one of the famous family's former town homes, may be your best bet. This elegant restaurant is noteworthy for its lovely atrium, which includes a waterfall and dramatic lighting. The menu offers diners Swedish cuisine that should not be missed. A three-course prix fixe meal may begin with an appetizer like smoked and seared foie gras or assorted Scandinavian hors d 'oeuvres; move on to such entrées as honey glazed duck or smoked venison, and conclude with one of the chef's own special dessert dishes. Reservations suggested; business dressy attire appropriate. TRAIN: Q to 57th St

UNION SQUARE. Laurent Tourondel's culinary caper (the B stands for "Bistro") in the Flatiron District has really caught on with the cool crowd. Set on the third level of a restored townhouse this upscale seafooder features suede covered walls, walnut tables, bone china and (most notably) a retractable roof. Fresh fish and shellfish, presented at the table, include Chilean turbot, South Pacific swordfish and Tourondel's signature Cantonese red snapper. For more terrene palates, there is a seasonal meat or fowl dish. The more casual first-level (the Fish Shack) recalls a New England fish house and features ditties like fish & chips and clam chowder. TRAIN: 4, 5, 6, L, N, Q, R, W to Union Square-14th St

UNION SQUARE. Marble columns and atrium spaces handle the sizable crowds that this renovated Union Square bank attracts. A massive raw bar, excellent seafood, "cool" jazz room and the option of outside seating have made Blue Water Grill a haven for young downtowners and those who appreciate a variety of delicious seafood dishes and first-rate service. Reservations recommended. Dress is business casual. Daily lunch prix-fixe $24. TRAIN: 6, N, R to 14th St-Union Sq

MIDTOWN EAST. Those who appreciate life's finer amenities dine frequently at Caviar Russe and lend much applause to the space for its elegant environs and first-class service. Tables sit a level up from famed Madison Avenue, affording the well-heeled patrons scenery befitting a meal of caviar (of course) and Haruo Kimura's legendary nigiri and maki. At $45, the three-course Sunday brunch is an affair to remember ­ one that forces the diner to make some tough decisions. Will the appetizer of choice be lobster bisque or a potato pancake with red caviar? And for the main, caviar eggs benedict or jumbo shrimp cocktail? Serious matters, indeed. TRAIN: E, F to 5th Ave; 6 to Lexington Ave