I say try out all three to figure out which one you enjoy most. If you pick something on someone else's recommendation and don't have fun playing it, you're not going to enjoy playing it any better just because it's the popular "meta" job. I've got WAR at 57, PLD at 50, and DRK at 47. I enjoy WAR well enough but I usually will only tank for free company members. Dark Knight on the other hand, I enjoy so much I am considering maining it. As far as paladin, I found that a bit boring and got to 50 mostly just for completionism. It may be less boring now that the 1-2-3 isn't the only rotation, though.