Which class does the most damage?

The title.

 

uncertain for the future, even now it's debatable

 

right now I believe it is either assassin because +80% damage when in vanish or archer with a glass build like rage gma or divzer.
in 2.0 we can only speculate but the assassin archetype shadestepper has the potential to be the highest damage in a single hit because of stacking a large amount of damage buffs (If an enemy has 3 Marks and 70% of their health or more, your next hit will deal triple damage, Multihit will deal a single devastating hit. If you strike the enemy from behind, deal double damage, If you deal more damage than 2x of your Max health in a single hit, deal 20% of the damage to other nearby enemies, these are just the ones currently shown off from twitch vod too so probably will be more) although for dps instead of just damage in one hit im not sure, I would guess one of the mage ones perhaps but thats purely guesswork.