For sure most iconic character of HxH was always Kurapika.
This man is like real legend.
Arguebly best arc of HXH: York New City based on his adventures. This dude never act stupidly...he is cruel, determinated, smart and do everything what he need to achieve his goal.
Unlike Gon Kurapika is deep character that has worser background then any other mc. He saw hell...and he ready to threw himself there for just opportunity to achieve his goal.
When you watch his arc you litteraly don't care about Gon and children games...no you watching on real crazy shit with tracking target, with real fight to death and much more.
Based on Kurapika character was created another character Sasuke from Naruto.
Kurapika character became etalon of how you should write avenger line.