Kakashi and Naruto of course.
All Naruto's fox fights have been insanely awesome, and Kakashi just ends everything right then and there when he gets tipped.
In Part 1 lots of people were pumped up to see Naruto get angry and use the Kyuubi's powers. Since he's constantly put down for being a low class ninja by the elites, it's nice to see them in shock.
But all in all I have to say Kakashi. His "rampage" was mostly off-paneled but that's not the only thing out there...
my favorite was when Haku died and Kakashi started owning Zabuza (his will was a bit shattered with Haku's death but it didn't take away from the scene).
Hes actually just this passive guy, only using genjutsu to get it over ASAP and to leave.
No one wants to see his true potential.
And because of that, stupid ****ing weakless fodders want to kill him but they couldn't even do it.
Sasuke had to kill those pieces of shit on the spot.