Usually on online auction, like eBay but not eBay, for cheaper prices. I also check Amazon.co.uk and Play.com if they have cheap prices, mostly for older games. For pretty new games, Game.co.uk seems like a good choice. And if I preorder something and want it quick, I take the cheapest local online store. I live in Finland, by the way, in case you were wondering.
Oh, and occasionally I can find something very cheap in real stores.







