Age of Conan... Being a big fan of the books and movies, I found this to be right where I left my winter jacket...
Not to mention that, although it was the most debatable thing in AoC, the combat was a fine upgrade to the push-button-have-guy-commence-awesome approach that left me feeling a bit bored with other MMO games... The combat system in AoC actually makes you work to achieve awesomeness, which not only brings a heavy string of micromanagement into play, but also it doesn't leave me feeling that I got killed cheaply due to the fact that other MMOs' rely more on numbers and stats and LVL
Keep in mind this is just my opinion, I'm not bashing anyone's favorite MMO, for I find them all, including Age of Conan, to be equally horrible, you just have to pick which form of horrible irritates you the least... For me, that was Age of Conan.