The "We must get strong episode," had some of the most memorable quotes in it for me.
"Well that sure was a long trip,"
"We didn't go anywhere! Its only been 2 seconds!"
"Yeah, but 2 seconds here is like, 3 months there, where we trained and got stronger!"
"We didn't go anywhere!"
"I don't wanna train, training is such a pain, and well, explaining it is such a pain, too..."
"How much pain is this guy in!? And is he really a Shounen Jump main character!?"
"Well, effort, friendship, victory, that stuff is all new its all modern now."
"And you better not write your name on any old fitness instructor because I can recognize my handwriting."
"COULDN'T YOU RECOGNIZE THE FITNESS INSTRUCTOR?!"
Another super memorable one was when they went to the Dentist...
"Oh yeah? Well I can't go a day without getting a good drilling done to my teeth!"
"Well I like to join drilling competitions and drill 'em good!"
(Inside their heads: He drills his teeth every single day!?
What the heck is a drilling competition!? What kind of mad man does that!?)
"I won the game of life! I am a winner!"
"You may have beaten the game of life but you're still a loser in real life."
"We'll meet again in 2 years, at Saobondy Archipelago!"
"Where the heck is that!?"
During the time travel moment in the Sket Dance x Gintama crossover: Tuturu! Made me so happy.
When Kagura walked up and said Jugem Jugem's name and Shinpachi yelled, "Don't say it like its easy to remember!"
Or when Katsura did his rap. "Nationalism is Joy, joy is nationalism!" then he turned on Elizabeth, "You! I know you talk behind my back when I'm not looking! Talk darnit!"
Or the internet chat episode, "Post Sayaka x Gintoki 1 thousand times or in 3 days you'll die!"
"Did you see that!? What are we gonna do fruits punch samurai!?"
"I am this highly ranked despite being the most disgusting character ever." - Kondou
"My new goal is to become king of the samurai!"
And I better stop now.... ^^;;