I think the City of Heroes community would be up there, at least. The Player Questions forum would often have questions answered within minutes, if not sooner. The creative people produced some really amazing character costumes and SuperGroup bases. There was a community-driven newspaper , of all things. Some of the more technical players hacked apart the game files, procuring the real numbers behind the game's powers, and encouraged the developers to add the information to the game's interface. The number-crunchers had things down to a science, to the point where they convinced the developers to alter animations by fractions of a second to bring things into balance. The Repeat Offenders network broke everyone's expectations of what different classes could do, and the Titan Network drew all of the third-party efforts together. Of course, City of Heroes is gone now. However, prior to the game's sunset, the community worked day and night to save the game. Mercedes Lackey authored the letters sent out to companies like Disney and Valve trying to find someone to buy the IP from NCSoft. Alas, their efforts ultimately failed. However, the community still isn't defeated. Instead of giving up and playing a different game, a group came together and are in the process of building City of Heroes' spiritual successor, City of Titans .
