Nostalgia
One of the things I value is experiences. I want to experience things, not necessarily for the sake of the experience itself in that moment, but so I can add it to my repertoire of knowledge. I can then talk about it, write about it, or dwell on the memory of it; and I can learn from it so that I have better experiences in the future, or so I can help other people with things related to that experience.
But from time to time, I'll feel a wistful longing for the past: nostalgia from a game I played years ago, for that feeling I can't have again--at least not through the same game, since the freshness isn't there anymore. But, in many cases, my nostalgia for games is more about the community. There were games I played that were booming with activity, everyone was just figuring things out and secrets were spread through the text of in-game chats. Even if the game is still alive, the friendliness is gone; or far more rare, and it's easier to look up a video guide or wiki article. There are no longer secrets that pass only through a ring of friends, not until the next game comes along that can recapture that feeling.
Go back farther and there are games where the secrets would be passed only through word of mouth outside of cyberspace. Well, I suppose I'm too young to have had an experience like that, or I wasn't in the right place in the right company for it to happen. Right now, I can create new memories while still appreciating what once was. And, it isn't like it's the last time I'll feel a sense of excitement and community from something--even if it isn't from a game.