Out of the ones you mentioned, ranger. But easiest, imo, is necromancer. I run full bezerker minion Reaper and she's pretty hard to kill. Minions add toughness, and the more mobs around you, the tougher you get with Rise! I use greatsword and dagger/dagger (for bleeds and healing myself). Giant meta attack that kills everyone? No problem, pop into shroud for safety and use skill 4 to rez folks. Great fun for open world. Soloes most dungeons with ease also.