The teams first fight vs the Demon Brothers. The build up and pace was everything Naruto series should've been from start to finish.
If this fight had been in the later episodes, there would've been one emotional backstory, two inner dialogues and 3 talk no jutsus. It's actually one of the better scenes in the whole anime to me.
And I love this in depth video about them which further emphasises why I like it so much: