Started rewatching the other day, I just finished the Haku/Zabuza arc. Their deaths still get me, all these years later...
The writing is so smart in that first arc. Naruto, Haku, and Inari all basically having the same backstory (loss of parents/abandonment) and showing how they all coped in different ways, woo. The way it sets the backdrop for the rest of Naruto's story and character.
Honestly, seeing how it all starts out (I don't know if Naruto actually ends up being Hokage or not in the end?), Naruto really has the setup to be the best underdog story of all time. Not even exaggerating.