Reply 20 of 67, by armani
I have nearly 300 big box PC games (going to downsize a hefty portion that I don't really play soon), and I am extremely anal about everything regarding them.
Anything that came with the box a long time ago, including shrinkwrap, price stickers, ancient printed supplements, receipts all stay in the box. I am also very uncomfortable regarding mixing and matching with certain boxes, such as putting contents that came separately for one big box (at one point) inside another of the same big box I own, but on rare occasions, this rule doesn't apply, usually when the game is so rare that it would just be a bigger pain in the ass to hunt down another copy. I have only done this with a few boxes to date, a super HTF US big box variant of Theme Hospital, Powerdolls, and Twisted Metal 2. I would not open any of my sealed boxes, even though I'm definitely not one of those people who buys sealed games just to resell them later.
I will make an exception. If the game is common enough, I will open it or suggest opening it.