I say Wizard.
Its versatile. Facetanking mobs with melee build and permanent frost nova, then switch to perma-archon facemelting mode. (lol both abusing critical mass)
DPS slightly lower than DH but it has waaaaaayy higher survivability.


DH has high dps but it gets boring real quick.
Getting killed by the malaysian latency boss is not fun at all.
It all boils down to how fast can you react and press smokescreen or shadow power: gloom.
Even if you try to stack a decent amount of resistance, you still die faster than most other class in the game.