Private server Roll call?

The glory days of mmos was the stuff of legend, and I love a good private server that relives the good old days of a specific game.

If a game was so great why did you leave?

I hate this comment whenever I talk about how good it used to be. The answer is simple, the game I loved so much tried to keep up with the hype of newer games and came out with expansions or patches that destroyed the spirit of the game, or simply retired content that I enjoyed.

Private servers that host a game at a pervious stage  is the best way to relive those glory days. One such server was Uthgard. It was a DAOC pre ToA server with all the feel and fun of the good old days with Dark Age.

TL:DR:

What are some of the popular private servers out for each game (if any) that runs on a vanilla or close to a vanilla state?

For:

WoW?  Dark Age of Camelot?  SWG?  EQ? Acheron’s Call?  Other?