Scout/Savage/Predator/Warlock are the easiest classes to lvl with

I think to solo Savage or Predator are probably the easiest classes after that warlock and scout (scouts damage is great but it needs hp abso). After that Guardians, quite tanky but they are annoying when they are below like lvl 75 ish.

I'm not sure about sage but I think str dragon sage should be good too, similar to guardians except they get their AOE/HP leech faster.