I'm sure all of us like opening a game for the first time to release it from its confined restraints also know as factory sealed shrink wrap. And when you have a backlog, keeping a game in its shrink wrap until you're ready to play it make is feel just as new since you're opening it for the very first time as if it just came in from the mail. Just make sure that game didn't come with a voucher for DLC.
I made the mistake of not opening my launch copy of LBP2 on the PS3 I ordered from Amazon. The Amazon version had Ratchet & Clank costumes for Sackboy, but by the time I opened it, it was past the voucher's expiration date. I tried redeeming the code, but still no go. The same also happened when Gillette and Sony were doing a deal where you get free DLC for certain PS3 titles depending on the Gillette product you bought. I bought a razor which gave me InFamous 2 DLC. I kept the packaging until I was read to play the game, but by then, it was also past the redeemable code date.
Thankfully, this wasn't always the case. The voucher for the orginal Alice that came with Alice: Madness Returns was still redeemable after its expiration date. The same went for Dragon Quest Heroes when I finally bought my PS4 last Christmas. I had the game already bought, but saw no need to open the game because I had nothing to play it on until recently.
So make sure you quickly redeem codes when it comes with a new game. Otherwise, you might miss out on the goodies.