What is Log Horizon?
Log Horizon is an anime based on a Light Novel about people inexplicably appearing in a world that resembles an MMO they played called Elder Tales. After a new expansion for the game had come out, thousands of players awoke in the game world. They don't know why they are in a world that resembles the MMO they played and they don't know how to get home.
Elder Tales was just a regular MMO like EQ, WoW, or Ragnarok Online. It wasn't even a VR game.
Where can I watch it?
It is available to watch subbed on Crunchyroll
http://www.crunchyroll.com/log-horizon
Why should I watch it?
It's the best MMO centered anime there has been in my opinion. Other people also agree with this sentiment.
Better than .Hack? Yes
Better than SAO? Definitely
The sad thing is that we haven't even had a lot of good anime based on mmo's even though it is such a topic worthy of being explored.
The author of the LN plays western RPG's, makes appearances in western message boards, and definitely is someone with the passion for these types of game writing about them. An episode where a bunch of new players were doing their first dungeon run together reminded me doing runs of VC (Van Cleef) with unexperienced people in Vanilla WoW.
Supplementary Material
The World Map of Elder Tales is based on our real life Earth map, but the world is half scale. It will take half of the time to get from one end of Japan to the other for example.
A lot of the major cities in our world are the basis for the major cities in Elder Tales
Classes of Log Horizon