Tribeca's Jonathan Burden (180 Duane Street, 212-941-8247, jonathanburden.com) specializes in English furniture. It's like taking a trip to London-minus the neverending flight-and I can always count on the store to have pieces with great scale.
Near Union Square Maison Gerard (53 East 10 St., 212-674-7611, maisongerard.com) offers an interesting selection of things by contemporary artists, mixed in with furniture, lighting, and objets d'art from major 20-century designers.
Yew Tree House (414 East 71 St., 212-249-6612, yewtreehouseantiques.com) is an Upper East Side shop that I go to when I'm looking for something unusual or with a lot of personality. I never go into a store with a shopping list, so Yew Tree is a good option for its unexpected surprises. The staff is also very helpful with special requests.
I often take clients to east Midtown's Interior Design Building (306 East 61 St., theinteriordesignbuilding.com). Housing more than a dozen of the city's top resources, it allows you to pick up on design trends after just a couple of hours inside. Must-visits are C.J. Peters (cjpeters.net), Lee Calicchio (leecalicchioltd.com), Démiurge New York (demiurgenewyork.com), and BK Antiques (bkantiques.com), which has a fantastic collection of lighting and accessories.
Nearby, the classic boutique Ann-Morris Antiques (239 East 60 St., 212-755-3308, annmorrisantiques.com) sells both locally handmade and imported lighting, along with a thoughtfully curated selection of antiques.