Don't Be Afraid of the Big Guys
Big name video game retailers tend to carry very negative reputations. Chains such as GameStop are labeled as a monopoly on the industry. While this can be considered true to an extent, that doesn't mean that you shouldn't learn how to utilize their services. In fact, if you take advantage of the big names you can end up doing pretty well in the end. Plus, it's only fair to give both sides of the story.
Of course, GameStop is always an option. I would consider looking into the GameStop PowerUp Rewards program. The membership fee might cost more than a local store, but the selection at GameStop is always going to be really solid. I would say that it is not the best idea to trade in games here, because you can get more money elsewhere. However, you can get pretty decent deals on pre-owned games, with the store frequently running specials on these titles such as "Buy 2 Get 1 Free."
I want to point out an emerging force in this industry - Best Buy. The store already reigns supreme in the electronics arena, having put several other chains out of business. Recently the retailer decided to expand it's gaming department by offering a trade-in program. You can tell Best Buy is trying to follow suit with GameStop by offering a similar rewards club.
The cool thing about Best Buy is that you can use a handy dandy calculator on their website to find out how much money you'll get for trading in games, so you can plan your gaming finances accordingly! While you won't get any cash for your games, you can use the money you get from them on ANYTHING in the store if you so desire. The retailer also offers deals to consumers if they pre-order or trade-in games. Plus, Best Buy even has pre-owned titles too! It is certainly a good thing that Best Buy has really dug into the gaming industry, because it creates more competition. Hopefully, gamers will see the benefits of this in the form of lower prices!