Two great buildings in the Flatiron District:
The Grand Madison vs. 4W21

The Grand Madison, 225 Fifth Avenue, at 27th Street
If your New York City dreams involve white glove service in an elegant, historic residence, a condo at the Grand Madison (top right) might be just the place to call home. Built in 1906 as the Brunswick Hotel, this classic prewar building overlooks Madison Square Park. The 12-story building features a full-time doorman, video security, a concierge, hall porters, a fitness center and a landscaped courtyard atrium. Prewar details complete the picture of a true classic, but with the added cachet of an exciting downtown location with a great park nearby.

What makes the Grand Madison special: Pre-war elegance and details (like 11-foot ceilings) combined with top-of-the-line modern luxury finishes in a landmarked historic building.

4W21, 4 West 21st Street
If you’re a thoroughly modern Millie (or Mark) with a love for glass and steel and having everything at your fingertips, 4W21 (bottom right) might be the perfect fit. This Hugh Hardy-designed high rise built in 2006 takes inspiration from the area’s traditional loft buildings, albeit with a sleek, articulated facade of glass and steel. This 17-story condop (a co-operative building that has condominium-like rules) offers a long list of details and amenities: solid core doors, quarter-sewn oak flooring, a high-tech security and video system, 24-hour concierge, a 2500 sf terrace, on-site parking and a fitness center. Huge windows, spacious baths and closets and top-of-the-line appliances make this residence future-proof.

What makes 4W21 special: Sleek, distinctive contemporary architecture, loft-like feel and flexible apartment layouts, on-site parking, central air.

Which of these NYC apartment buildings is best? You decide.