What do you want to do?
Speedfarming, pushing solo, greater rifts?
Monks and barbs are always good, top tier solo builds and a must for 4 man groups as zdps.
Wizards are also great and by the looks of it, will be used in 4 mans aswell.
For RGK it's been some discussion, lot's of talk about thorns lon necros.
Personally I will play barb from the start cause of IK and being able to farm paragon fast, will prob go over to DH after like 1000 paragon or something like that.
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