My favorite item I have is an unopened Pokémon Green. I have some other Pokémon stuff, but for now I'll post some pictures I took of Green a while back. Well, it used to be unopened until I opened it.

The front side of the box. I guess Game Boy Japanese games way back then were inside a plastic slip (either that or the collector I got it from placed it in one to protect it).
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The back side of the box.
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Japanese game cartridges game with a plastic cartridge protector. Sucks how that wasn't the case in America and you had to buy them separately. Also, I could tell the game was kept preserved very nicely, as it literally still had a faint "new plastic smell". Smelling that pretty much made me the hardest I've ever been in my life.
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The cover of the instruction manual.
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Inside of the instruction manual #1
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Inside of the instruction manual #2
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Inside of the instruction manual #3
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The back cover of the instruction manual.
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Here's something I don't think the American version came with, a complete map of the Kanto region, and it's a pretty good size as well, about the size of a medium poster.
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A close-up of the map.
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Since only ten images can be used, here are some links to three more pictures of the inside of the instruction manual.

http://i.imgur.com/qgdsTJm.jpg
http://i.imgur.com/z8KEuJA.jpg
http://i.imgur.com/oq6B7f2.jpg