I used to play World of Warcraft (main was a human rogue), but I pretty much played it out and lost my interest in it. After that, I got into a free MMO called Eden Eternal, and I liked that for the fact you would dress up your character in so many varieties of ways, but the costume pieces were extremely expensive (even the ones that were just for aesthetics and didn't add to any stats). I also tried the Final Fantasy: Realm Reborn MMO, but I didn't like it all that much. Combat felt really slow and even leveling in the beginning took a while, so I could only imagine how drawn out the process would be around level 50 and beyond.

Haven't played any MMOs for a while now, though. Just haven't really found any that wowed me.