StingingVelvet: Hoarding is a pathology, collecting is a hobby.
meudoland: getting enjoyment by just possessing a game and not by having played it, is a pathology.
It's about more than just having it, it's about looking through the box, seeing the art, seeing how they advertised it, feeling the texture. I love looking through my old PC big boxes and reminiscing, or just seeing all four Fallout games lined up on the shelf. It's a nice collector feeling like having a complete run of a comic book series (even if some issues suck) or having all of Ridley Scott's movies lined up by year (even if some of them suck).
I think if you collect EVERYTHING then there is something wrong with you, or if you collect useless things. That is hoarding. Loving PC games and collecting them in their original boxes though? Nothing wrong with that.