If its a new game, then Walmart. My Walmart is almost 100% always guaranteed to have a copy of it. If its a old used game, I'll check out prices on eBay then go compare to my local EB Games. Depending on who is cheaper/has it, I'll buy from them. I don't like trading in my old games because I know as soon as I do, I'll wanna replay it, and won't be able to find it. And I use Steam for buying PC games, even if it does like to screw up my computer and cause harsh lag.
Tenkage said:
What is Steam, I keep hearing it but I don't really know what it is
Google is your friend.
http://en.wikipedia.org/wiki/Steam_(content_delivery)
"Steam is a digital distribution, digital rights management, multiplayer and communications platform developed by Valve Corporation. It is used to distribute games and related media online, from small independent developers to larger software houses. Steam also has community features, automated game updates, and in-game voice and chat functionality."