I like Counter-Strike: Global Offensive, but I loved the original Counter-Strike. While CSGO is the prettier, more polished version of the same set of ideas, so many of the maps, so much of the feel that I loved, isn't present in the latest iteration.
The original Counter-Strike is still available to play, but its final update, 1.6, isn't the version I want either. I want beta 5.2, or thereabouts, from back before Valve bought the game and its rougher edges got sanded away.
That's me. But I'm here to ask you: what live service game would you like to see relaunch and preserve an older version of itself, as World Of Warcraft: Classic has? And what version would you want?