When I used to have SNES/NES/N64 games, the cardboard boxes would get bent and crushed ALL THE GODDAMN TIME. I ended up throwing them out and just keeping the manuals (most of which I lost since I no longer had a box). However, in any other instance, I always keep the games and their cases and manuals. In fact, I refuse to buy a game unless it has a case and manual. I have a CD binder and I keep all my cases in one place, so I don't see how space is an issue. PS2/X-Box/Gamecube cases hardly take up that much space. If anything, just keep them all in a big box, and keep the games elsewhere. Problem solved.