What's the best free MMORPG

[okr]

I've never played a MMORPG myself, but I've recently read some interesting articles, e.g. this one, about Runes of Magic from Taiwanese developer Runewaker.

It's in the OpenBeta atm and the preview articles not only said that this one has very good graphics for a free MMO game, but it could also be one of the best so far.