There are many wikis about gaming out there on the web. You can more than likely find a wiki available for any modern game or series of games. There are also wikis for much older games, and if there isn't one, then it can easily be created.
You can find a wiki here for the whole Battlefield series of games from 1942 to Battlefield games that are still in production. This wiki contains a lot of information for there games that have already come out, but it lacks information for their newer games such as the new Vietnam expansion for Battlefield: Bad Company 2. It could lack information because very little information about the game has actually been released and very few people may have had the opportunity to play it. The game comes out December 18th for PC, and December 21st for both PS3 and Xbox360, so much more information will be added to the Battlefield: Bad Company 2: Vietnam portion of the wiki once the game is officially released.
There are many, many more wikis out there. For example, you can find wikis for the Fallout series, or the Mass Effect series with just a simple google search. These wikis can contain any kind of information such as backstory, voice acting information, appearances, their purpose in the game, and much more.
