The neutral pacifist Pandaren DoubleAgent, who pioneered the art of leveling without ever picking a faction, has reached level 70! It took 12 days of gathering resources across the Wandering Isle to level up from 60, all without ever pledging himself to either the Alliance or the Horde.
Pandaren were the first neutral race, introducing a race shared between both factions in 2012 during the Mists of Pandaria expansion, which meant that it began the leveling process without one.