Elder Scrolls Online has also done one of the best jobs at keeping the economy running well out of any MMORPG I've played. They have a pretty ingenious way of destroying gold to keep the economy from inflating. Basically the only viable way to sell things in the game is to get a guild trader. There are a limited number of them in the game, and not all are equal. Guild traders in main cities for example get 100x the player traffic as traders in the middle of nowhere.

So there is a lot of competition to get a good guild trader, and guilds all bid large sums of gold to try to get a good trader. The winning bid for a trader gets the trader for 1 week, and the gold spent on the winning bid is destroyed. So it turns into a self balancing system, because if there is too much gold in the economy then the guild trader bids go up really high and take lots of gold out of the economy every week. If there is not enough gold in the economy then it isn't viable to make such a large bid on the guild trader, as you won't have any chance of making enough money back to justify the large bid, so bids go down and more money stays in the economy.