The PlayStation 2 is one of the most beloved consoles of all time, marking the pinnacle of a type of gaming that we've now left behind. There was no Netflix back then, a 16MB memory card was considered excessive, and online capabilities were appalling. Ahh, how different things once were. Something that really brings home the age of the PS2 is the fact that many of its rarer games are beginning to re-emerge from obscurity and appear as valuable collectors' items. Those humble DVD discs that once lay dejectedly in your local GameStop bargain bin could now be worth hundreds of dollars. In many cases, these aren't even great - or even necessarily good - games. Their value could have gone up from the fact that they had a small print run, were unceremoniously banned in many countries, or are limited edition releases that inevitably grow in value exponentially over time. If you're nervous that you might spot a valuable game in this list that you traded in for $5 credit a couple of years ago, then you probably should be. At least you can learn the lesson that you should treat your old games with respect, and that instead of selling them you should hoard them like a video game-obsessed dragon.