Episode 33, it was the first Naruto episode I've seen and it got me hooked.
It begins with Sasukes "dream/memory" about I need power etc.
That part showed a part of Sasukes tragic history. than it switches to action the formation InoShikaChou! (That part with Chouji about being fat is funny )
After their ultimate formation fails, Neji kicks in.. then Sasuke goes all out with his Cursed Seal, breaking Zaku's arms.
So I say ep 33