Though New York is famous for its vintage clothing stores, it's rare to find a place with a good selection of clothes and accessories for men. Here's a list of shops in Williamsburg that have equal, if not more clothing for men.
Stella Dallas is a great vintage store in general. For one thing, it's huge. The store is divided into two sections, with newer vintage ('80s) in the larger front room and older, rarer vintage ('50s and earlier) in the back room. Women's and men's clothing is separated. Here you'll find a fantastic selection of men's shoes (particularly dress shoes), t-shirts, dress shirts, pants, jackets, sweaters, hats, scarves, sunglasses, and even suspenders. As far as men's selection in this neighborhood, Stella Dallas has the most to offer.
This smaller secondhand store has a nice selection of men's clothes, particuarly t-shirts and dress shirts. There are racks and racks of flannel. Though there are a few shoes, one would be better served at Stella Dallas if you are looking for accessories. But the clothing at Monk's is very affordable and in some ways, the men's selection is better than the women's, which is focused more on cheap thrifted clothing rather than one-of-a-kind pieces.
Though the women's section is much larger, Beacon's Closet does boast a fairly large men's selection in the room to the left of the cash register, with clothing and shoes. Beacon's is a buy/sell secondhand shop, so you can bring your unwanted clothing and sell it for store credit or cash. They are probably always in the market for men's clothes, especially coats and jackets.
Only on Sundays:
If all else fails, there are a few booths at the Brooklyn Flea specializing in men's vintage. The Brooklyn Flea is a great place to look for blazers, ties, vests, shirts, and shoes. Occasionally you can find an incredible vintage suit, hat, or bag. Don't expect to be overwhelmed by the men's selection, but the Flea is good for the serious male vintage shopper who is willing to put in some time for browsing.