They're all basically neck-and-neck at this point, but I guess I would have to go GNB>DRK/PLD>WAR for ascending ease of play [WAR=easiest, but only by a bit].
...Unless you're in a situation in which you can make a special and active effort to milk the unique affordances of TBN or ranged spell phases for additional uptime, in which case it's just GNB/DRK/PLD>WAR.
