Naruto trying to compliment Hinata on the work she's doing in Chapter 3. The key word being "try".
Chapter 4. Naruto pranks Kurenai so hard she temporarily flips out. He's using a genjutsu to make it look like he very hastily put on a green jumpsuit and dyed his hair black in an effort to emulate Maito Gai. Kurenai doesn't recognize the illusion despite being a genjutsu specialist.
More to the point she is so horrified and angry at seeing that,that she never thinks to check that it is an illusion. She goes on to teach the kids why she was fooled as a lesson on deception.
The Kyuubi calling Jiraiya a frustrated old virgin to his face.
From Chapter 7 after the battle where Kurenai told Konohamaru and Hanabi to flee while Team 8 fought the enemy:
Kurenai: Can you track down Sarutobi Konohamaru and Hyuuga Hanabi?
Konohamaru:<from the nearby trees> Yeah?
Naruto: He never does what he's told to do.
Gai and Lee are just as amusing as they are in the series, but special mention goes to the celebratory dinner where Lee drinks some of Gai's sake and drunkenly attacks Neji - successfully, which is something he's been unable to do until that point. Gai did warn him to not underestimate his opponents...
Later, Naruto decides that if he'd known how getting Lee drunk would turn out, he'd have made sure it happened. Frequently.
Lee: Oh, Naruto, you sound so bitter. Surely the Power of Youth has not left you forlorn? Naruto: One of these days that stuff's going to make sense to me, and then I'll know I'm in trouble.
The next chapter after that, Naruto panics right out of the gate on the Chuunin Exam:
Naruto: (thinking)Oh, Crap, it's even worse! They want me to do math!
During the Chuunin Exams, Naruto breaks Orochimaru's nose. We're treated to the next few lines of him trying to speak through it.
Orochimaru:"Well, thab's juds ab well. All I'b done id tick a fuz in their petty liddle bomb. Led the olb man deal wid it if he can."
Then we are treated to his creepily funny reaction to that: annoyance as he realized how ridiculous he sounded talking that way, followed by pinching the nose, wrenching it back into position, and asking "Now where were we?".
Kurenai threatening to hire her team to burn all of Kakashi's dirty books. He's so worried he is cradling one protectively afterwards.
This exchange between Shino and Naruto, when Shino finally connects the proverbial dots:
Shino: I am not stupid, Naruto. (counting off his points on his fingers) You have a chakra capacity exceeding that of most jonin, even thought you have just become a genin. You can master highly chakra-intensive techniques with far more ease than you can master less demanding ones, suggesting that your chakra capacity is literally filled to overflowing most of the time. Even the most forthcoming adults of Konoha are strangely unwilling to discuss the reasons why you are shunned by most. There are no physical relics from the nine-tailed fox, even though our history texts state that it was slain by the Fourth Hokage. Your physical stamina is superhuman and you recover from minor injuries at a rate unprecedented for someone not under a physician's care. Your birth date is a matter of public record, as are the unusual birthmarks on your face. And finally, when we spar, I can have half my colony feed off of your chakra until they are replete and you do not even notice. (to Naruto) I am neither stupid nor unobservant. (Beat) Naruto: ...you stuck your bugs on me when we sparred? That's cheating!
Even if Naruto's not laughing about it, the mental image of one of his Kage Bunshins stumbling across the Sand Siblings in the Forest of Death and choosing to go out by giving Gaara a noogie.
Another one of them mooned Neji before expiring.
Tsunade attempts to drive off Jiraya and Hinata by making a counter-offer for her to return to the village and become Hokage: Hinata takes up apprenticeship (read: indentured servitude) for Tsunade for 6 months. She thinks no one will go for it. Hinata accepts immediately.
Iruka ending up with a lingerie store named after him. It Makes Sense in Context* He won so much by betting on Naruto against Neji in the Chuunin Exams that several Hyuuga Elders nearly went bankrupt and had to pay him in assets, including several properties around Konoha. He noticed that one of the shops, Pandora's Secret, was being unfairly overcharged for rent, so he renegotiated with the owner on the condition that it be "their little secret," since he didn't want all his tenants trying to renegotiate rent. She misunderstood and renamed her store "Iruka's Secret."... But it's only funnier when you get the context.
Iruka: (to Naruto): "This is all your fault, you know."
And the owner wants a picture of Iruka for her storefront. Naruto gets one for her.
The whole business of Iruka dressing up as a rich foreigner to hustle Konoha's elite by betting on Naruto against Neji in the Chuunin Exam matches. Naruto is thoroughly impressed. It's later revealed that he won so much that he nearly bankrupted several Hyuuga Elders, forcing them to pay him in alternative assets, including debts owed by third parties and several Konoha properties.
Naruto interrupting a "Gai-Sensei!"-"Lee!" exchange by puking on Gai's feet. It's not because of the exchange (Naruto had just helped Lee test the Omote Renge, and was feeling ill even without hitting the ground), but the timing is just too perfect.