Haha. For laughs... my vote goes for Naruto attempting the Chidori and his getting nailed in the ass by Kakashi.

For overall pimpness. The one that Mae posted.

What about some where:

Jiraiya is "training Naruto on summoning" or "gathering information"
Naruto using his Kunai + Expliding tag 1000 years of pain on Gaara
Sakura getting her head pounded in by Zaku