I was on the lookout for a Sega Game Gear - one of the first hand held video game systems- and had been unable to find one, when Slacker's was recommended to me.
On the first call to them, they advised they had one in stock and would even throw in a free game if I'd purchase it from them.
They had very reasonable prices and upon visiting the store, I discovered a treasure trove of used games at very affordable prices.
The staff was very friendly, they were knowledgeable about all gaming systems and they were eager to help me find what I was looking for.
They also buy cd's and games if you're looking to get rid of some things that are cluttering your home.