I was in town (Fredericksburg, VA) early enough today that I was able to hit a couple of pawn shops and three thrift stores. If you know what the price of things are, these can be places for incredible bargains.
My favorite pawn shop so far is Spotsylvania Gold and Pawn. Courteous staff, great deals, and a 30-day “lemon” guarantee on merchandise. This was the same place that sold me the TV/VCR combination. A couple of other pawn shops I've been to (that I won't mention by name) seemed more adversarial with the sale, or set the price above what a new item would cost. Now, I understand that they can't give the seller of the merchandise anywhere near what the item is worth, but they shouldn't be trying to skin the buyer, too.
Of the thrift stores, my favorite is still the Salvation Army Thrift Store. They're willing to make deals with you and treat you with respect. Other places give me the impression that they're doing me a big favor by opening their doors. A deal's a deal, but it's nice to have a pleasant atmosphere, too.
One trick that I've used a few times to make a good deal better is to hesitate a little when looking at something I'm interested in. Silence is a very powerful tool. Often the person who speaks first loses the edge in the negotiation. For example, say I ponder a little over a set of coins that are reasonably priced. After a few minutes with the guy standing there (he really can't leave me with the coins out, can he?) and me saying nothing, he might volunteer a lower price or offer a deal if I buy in quantity just so that he can go do something else. (Cha-ching!)