I thought he meant which class isn't delegated to b*tch jobs like conveyor belts, flamethrowers, balconies, kiting, soaking specific mechanics and so on. Not which class doesn't need to worry about standing in the fire, because all of them do need, obviously.
If I'm wrong, and he meant simply which class has easy rotation, then I'd say in no particular order: surv / mm hunter, combat rogue, arcane mage, destro lock, ele shaman, fury warrior. Sadly hunters while being easiest to play are also hardest to get raid spot as (too many of them, cuz easy to play) and are usually assigned b*tch jobs due to mobility, aoe capability, kiting tools and so on. If warriors weren't kinda weak I'd suggest that, their low utility means most of the time you won't have to be "that guy" assigned to something like a paladin might be asked to bubble (hand of protection) someone or dispel or a priest might need to mind control, etc.