Healing Spheres:
Widely, WIDELY underated. Completely overpowered.
In my monks gear they sustain 161.4K single target HPS (assuming no overhealing obv) while costing 12k mana/s. In the current environment of infinite mana, they are beyond broken. I have yet to test them after the 30% cost increase, so I can't say whether it's still possible or not, but tank healing with them is very very effective w/o breaking the bank (mana). Try it out. Though it probably won't stay this strong for long.