Oddly enough, I didn't like the initial idea of tanking. Played with it here and there getting PLD and WAR unlocked at 30 to get the experience, didn't really hook me. Then I unlocked Dark Knight, and for me, tanking just clicked. I loved Dark Knight's MP reliance and constant balance between enmity, damage, and self-maintenance keeping me busy and focused as opposed to old FFXI's style of "spam provoke/flash and maybe cure or buff yourself occasionally, and yell at your bad WHM/RDM." It's a very active tank, and whether I'm stance-dancing for DPS, or stubbornly fighting an enmity battle against another tank who seems determined to try and take MT from me, it keeps me busy and focused on the game as opposed to dozing off pressing 1-2-3 over and over.