Salvador Monella
This is the largest, most well-stocked spy shop with the widest selection of gear of any spy shop I've ever been to. The vast array of different products, gizmos, and gadgets they have is dizzying. Some of the things they have I can't even imagine them existing, and yet these folks have them. They have all the normal stuff, hidden cameras, regular cameras, electronic bugging devices, electronic bug finders, telescopes, binoculars, covert-carry products, secret compartments to stash stuff in, and much more. There is gear (and books on the topic) covering the (very tall) walls, in the display cases, and on virtually every surface visible. Despite this extensive inventory, not everything they have is on open display, so if you have a product you're after, or an application or situation you are trying to navigate, talk to one of their helpful staff. I wouldn't call these folks "spy nerds," more like "spy curators." They aren't unknowledgeable kids fresh out of high school. They are seasoned pros, with decades of experience. This is evident from even the most casual conversation with the staff there. If you've got some spying to do, our some counter-spying to do, or are trying to root out the spies in YOUR life, give these folks a visit. For what it's worth, I have visited less than a dozen shops providing spy equipment, so keep my somewhat limited experience in mind. It is possible there are better spy shops somewhere in the world, but I've never seen one.
