My vote goes to Warrior Charge / intercept spam, nothing more annoying than warrior bouncing all over the arena. Intercept should share cooldown with charge (Cat Leap and Feral charge shares, why not Charge and Intercept?)
RoV comes pretty close, when playing on my lock i can't place portal on the elevators, my pet is stuck on every pillar / platform possible and the when you try to los something the pillar always goes down, always...