Lyric, Innovative Audio, and Stereo Exchange are all well established dealers. I think Park Avenue Audio may still be around, too, but it's somewhat more of a mid-fi store.
The stored referred to in Schipo's post is Lyric - they can sometimes be fine, and other times be obnoxious. Bob Herman's not a bad guy.
Sound by Singer has recently reopened on an "by appointment" basis only. Andy Singer can be obnoxious and arrogant.
Ears Nova is also by appointment.
CSA Audio in Montclair, NJ, is a friendly bunch of guys who are knowledgeable and have a lot of good product.
Audio Doctor in Jersey City, NJ, is very knowledgeable and has good product.
The most interesting store in Manhattan in my opinion is MSS HiFi, which is a big used equipment dealer. The owner, John Boey, is a character, but he often has great used equipment at bargain prices.
People selling luxury goods in New York City are often going to be obnoxious and have attitudes - in their defense, they deal with a lot of arrogant, entitled customers.