The scene where Kakashi giggles and blushes 'cause reading that come come paradise! book OWNS all!
That thousand years of pain is also quite funny!
And Gai and Lee of course! They are so stupid but yet so corageous and determined. They think they are cool but in reality everyone thinks that they are buffoons.
The two funniest pairs are Gai and Lee and Gai and Kakashi! Kakashi is so "hip" and Gai is so old fashioned!
Sakuras facial expressions are also invaluable!