To specify my vote for the 3D action mmo, it's the open world that makes it or breaks it for me. Vindictus bored me to tears in the end repeating the same dungeons and nothing but them all day, but the sheer sense of freedom I felt in TERA was staggering when combined with the combat system. It's hard to describe to people who have yet to play it, but the immersion is so much greater with the level of animation and the way combat and exploration flow into each other so perfectly.
