I was in NY a few weeks ago but B+H was shut due to holidays. It's easy enough to find. There's plenty of AV/touristy shops around but not convinced by them or the prices. B+H is at least a specialist shop.
When I lived in NYC I used to window shop here the odd weekend: Stereo Exchange
They have a couple of pairs big 800 series B&W speakers (800D and 803D I think ) on display, powered by mcintosh amps if I recall correctly. They also have some Meridian speakers out on the floor. They are more of a specialist store than the others mentioned so far in this thread - they have quite a small shop floor with demo rooms in the back. It was nice to go and look at stuff out of my price range every now and again.
J&R are great for computers and all other things electronic. They also have a good range of headphones, but I wasn't that impressed by their home audio section - the speakers they had on display weren't that impressive. Decent range of flat panels though.
Best Buy (like the US equivalent of Currys) have a couple of stores in Manhattan. One of the bigger ones I remember was on 23rd and 6th. Just like Currys they are decent for LCD and Plasma screens, but forget about finding any serious audio equipment there.
I never made it to B&H oddly. I always thought of them as a digital cameras/camcorder shop, but I guess they sell other AV/Electronics too.
Harvey Home Entertainment - 2 West 45th Street, NY. Top Class AV store with friendly and knowledgeable staff. I only went in for a ZP80 but after a while chatting was taken into a demo room and well entertained.