The easiest way to display all boxes unopened and have a pretty good theft security it to put each box into a transparent case with an anti-theft tag and remove the box at the counter. Many european stores do this because they don't have storage space so they have to display their whole stock. This is good, since you can get the box you want and take it to the counter and you can also see the amount they stock from each title. The protective case is actually used instead of stickers because this is a cheap way to get back the pricy rfid chip when the product is sold and it's impossible to open such a box without a special key or a chainsaw. (and the built-in rfid circuit has a much stronger signal than the sticker version and you don't have to pay for it, since you leave it at the counter)

ps: Used and discount stuff is usually just piled up in containers, but even then each one is boxed this way. Cd-s and dvd-s are also boxed along with other smaller things, like memory cards.