It baffles me, the amount of games that originally came in perfectly good, plastic cases that are now just a cartridge, or disc, all alone in the big world of video games. When it comes to Nintendo, they always gave you a cardboard box that typically ended up in the trash, thus boxed games for the cartridge based Nintendo systems are always going to be harder to find. But when it comes to Sega, or the disc based systems, there is absolutely NO excuse for these games to be loose, none!
I've seen a lot of loose Nintendo games, and since I understand that people trashed the boxes, and sadly the manuals, I understand why they're loose. When it comes to Genesis games, they're either loose, or boxed with no manual. I'm pretty strict when it comes to Genesis games, I see no reason in why they should be loose, albeit I won't turn down a good deal on loose Genesis carts that I really want to own.
Now that I'm going to be building up my Sega Master System collection, all of my games are complete (with the exception of my very first game before I even owned the system) and that is the way I want the collection to be! Master System games are hard to find as it is, let alone having to find them complete with the manual and in good condition, but that isn't to say it will be an impossible feat, and again I couldn't turn down a good deal on a loose SMS cartridge.
While reading through the manual for Hang On/Safari Hunt, under cartridge care it states "After use put it in its CASE", which hit me as funny. Sega knew people should return the cartridge to the case, why was it so hard for people to put the games back? The plastic case wasn't like the cardboard Nintendo offered, it was reusable.
Many of my Genesis cartridges are loose, but I would rather have them all complete. When it comes to disc based video games, I will almost never buy it without a case and manual, but if I find one super cheap in a bin at a thrift store I may pick it up. But it truly baffles me as to why people let discs and cartridges that came in plastic cases just float around loose.