I'm going to attempt to give a review of every shop I can think of in the city.
Fantasma
Location: Corner of 33rd and 7th 2nd floor
Take the 1,2, or 3 to 34th St. Penn Station and you can walk underground right into the building of fantasma
I don't know how fantasma is off the beaten path considering its right across the street from Madison Square Garden haha. But in any event Fantasma is a huge store and is becoming more of a museum for magic history. There is a sizable Houdini museum and a lot of famous magicians have donated memorabilia.
Other nice point of Fantasma is at any point you are bound to see Simon Lovell (with is trusty beer in hand haha) and David Roth. Not to Mention, running into Asi Wind, Ricky Smith, Doug McKenzie at a lecture. I'm slightly biased considering I used to work for Fantasma Demoing in Toys 'r' Us Times Square, but I have always felt there is just a well of knowledge at Fantasma.
Tannen's
Location: 34th btwn 6th and 5th Suite 608
Take the NQRW to 34th street and walk east on the north side of 34th street.
Tannen's is staple of the NYC magic scene. You just seem to have to go there. The networking that you can do within the "Tannen's Family" is quite extensive. I have been there twice. The first time left a very sour taste in my mouth and I didn't return for quite some time. The second time was ok. The downside to Tannen's is it's size. They are very busy and very small. There is not a place to come and work on a new sleight or really get a great opinion on something. It may just be a personal preference but when I go into a shop- yes i'm going to support the shop but I also want to enjoy my time. The second time I went in was a little more relaxed and I had a better experience. You have to give them credit for how extensive their inventory is too.
Halloween Adventure
Location: 4th Ave just below Union Square
Take the L,N,Q,R,W or 4,5,6 to 14th st. Union Square.
Some people may argue to not even include this shop in my review. After all, this shop is primarily a costume shop that supports itself for the year, from its halloween sales. If you go downstairs in this shop and all the way to the other end on the left hand side you will find a "magic nook" so to say. Steven Henriquez used to work there. The inventory is not extensive, and there is not a place to session really, but there is usually a rare or hard to find book. They also keep the basics in stock. The reason for even including this shop is it is a piece of NYC magic history. The "nook" used to be much bigger and there was a whole separate room for sessioning. All the current pros when they were coming up went through this shop and have been known to drop in from time to time.
Hopefully I didn't miss one, and if I have let me know, because I would like to make it there.
Hope this helped!
~Chrisfecto