Corrado Cutley on Clark in downtown Chicago has a very knowledgeable salesperson, and a decent selection. I buy the occasional sharpener or item on special, but mostly I just check in to chat knives (I can't say that I'm eager to pay full retail for something I can get marginally used for 1/3 the price on the forums). I try not to take up too much of his time, or distract him from other customers. And I turned him on to the forums!
Northwest(ern?) Cutlery, however, somewhere West of the Loop (800 W. Lake?) is another story entirely. Those guys don't know as much about their stock as Corrado, but wow! What a lotta stock they have! I can't help myself, I have to paw some of the items - but again, making sure never to distract from other customers. And some of the clerks are perfectly happy playing with the stock, and just chatting, when no one else is around. So I don't feel TOO guilty . . .