I just started playing this recently now that it's free. It might be my favorite MMO so far. The combat system is unparalleled. You control the direction of your swings, there are things like http://www.youtube.com/watch?v=T2X_SbZCHpc that make it more fun.

They gained 300,000 players in July alone from going F2P.
http://www.ageofconan.com/