There are plenty given the format and genre of the series. Here are some of the notable ones.
In one story, Nobita ate special sweet potatoes that, when ingested, allows him to sing using farts. Doraemon forgot to tell him no to take more than one, however, and the resulting Fartillery rockets him past his own house...from his friend's.
In the Nobita and the Winged Braves movie, when they first fall into the birds' world, Doraemon, Nobita, and Shizuka, are attacked by crow soldiers that call them "two humans and a cat," both of which are the natural enemies of birds. Doraemon's only reaction to this is to cry in joy since someone finally called him a cat.
In the 2011 remake Nobita and the New Steel Troops ~Angel Wings~, Doraemon uses a Translation Jelly on Judo, the brain unit of Zanda Claus note Nobita would rename him to Pippo, as Judo communicated in Morse Code-like beeps. However, Judo's angry ranting causes him to bounce, knocking off the Translation Jelly, causing Nobita to put it back on him four times until the boys finally blow up on Judo, yelling at him that there's way they could communicate with a bowling ball.
And then when Judo is transformed into a baby chick, the boys fawn over his cuteness... only to become irritated when they find that his personality had remained the same.
In a moment of visual humor, Suneo is running around in a state of total panic after Shizuka has gone missing in Nobita's Great Battle of the Mermaid King, while Jian is speaking with a guard. At one point, Jian just lifts his arm and clutches Suneo into place, without looking up nor saying a word.
In the English dub's episode "Battle Of The Dueling Nobys", Suneo (Sneech) teases Nobita (Noby) saying that he can only assemble model toys like his robot that are meant "for ages dumb to dumber".
From the same episode, when Doraemon is forced by Noby into using his time machine to travel back into the past to prevent him from buying the noodles, he utters this gem...
Doraemon: I just want the hands of fate to know I'm doing this under protest.
In the episode "Robotic Balloon", when Gian is practice singing in his room, Ms.Goda comes in and shout at him to stop singing as it's the worst. When Gian tries to argue she used his microphone to tell him to stop.
In the English dub, Noby's hilariously wrong answers to his U.S. history quiz using the Sequence Spray:
Q: Where was the Declaration of Independence signed?
A: At the bottom.
Q: In what year was the United States of America founded?