I have been playing since the Chinese beta began and have since accumulated hundreds of hours on the game. Before Aion, I used to play World of Warcraft for four years. My first MMO was Everquest 1 which I also played longer than any other (5 years).
My favorite class in Aion is probably the sorcerer, simply because I like to blow things up from afar. Aside from a short stint as a rogue in WoW, I always ended up with ranged DPS classes (and thus got rather skilled at patiently waiting for group invites).