Acknowledging Mettle's status as a meme on 4chan. Twice.
Just the fact that the Internet keeps mistaking him for being the Red Skulls son! First of all, he's half-black and half-jewish (which they can be forgiven for not knowing, it's not exactly visible anymore) but second, the Skulls appearance isnt even a mutation that could be passed on genetically, he looks like he does because he accidentally disfigured himself with his own poison.
Hazmat's various take-thats at Marvel Comics as a whole.
Hazmat in #10: "Today's gonna suck as much as all the others... but just a little bit harder. Because it's One More Day... with no end in sight."
In #34. "I thought they'd reopen the Academy in a day. Maybe two. But this Avengers vs. X-Men thing just keeps dragging on."
In #5, Finesse shuts down Striker's attempts to hit on her in an epic manner
"You're young, rich, attractive, powerful and entitled. All the makings of a selfish, unimaginative, and unskilled lover. I have more interesting ways to pass the time. And more interesting people to pass it with."
He then turns around and asks Veil if she wants to hook up with him, she shuts him down by snarkily saying no girl could resist him;
"And yet, I just did, I must have superpowers."
In #22, the X-Men visit the campus. Cyclops raises concerns over a re-programmed Sentinel that one of the students uses.
Also in #22, the issue-long Snarkto Snark Combat between Quicksilver and Magneto. Especially when Finesse quizzes Magneto about him sending assassins after Pietro and Wanda as a training exercise when they were younger.
Magneto: (whispering in Finesse's ear) They had orders not to hurt them. But don't tell him that.
In issue three, Valkyrie gives the girls The Talk and serves them mead. Tigra is not amused.
Hercules' appearance in the Avengers vs. X-Men tie-ins had two big ones, mostly for him being a Large Ham.
Posing nude for the class and everyone's reaction to it, X-23's in particular: While everyone else is shocked or embarrassed (and Finesse gives him an intrigued appraisal), Laura's bored expression while looking right at his junk practically screams, "Meh. I've seen bigger." And then he suggests wrestling with the strapping young lads there.
The fake-out fight leading to Hercules' monologue. It lasts the ENTIRE FIGHT!
Hercules: I am undone! O cruel fate, why have you cursed me so!
Striker: Dude, you are a horrible actor.
Hercules: Sophocles disagreed. Now silence, my monologue has just begun!
Hazmat getting prisoners to leave her alone in #4.
Grizzly: Hey, kid. You just got elected hostage. Do exactly what I say and you won't—
Hazmat: Get back in your cell. Or I'll give you cancer.
Grizzly: Okay, okay. Jeez. Used to be they'd just smack you in the mouth.
Julie Power's reaction to Striker coming out to her. It's all in the look in her face.
Her reaction to His public coming out is even funnier.
Klara Prast's first encounter with a Sentinel - "Run, Molly! I will restrain the automaton!"
The entire flag football issue is hilarious, from the running gag of Jocasta tasering everybody for foul play (complete with frizzy hair), to Wolverine getting revenge on Giant-Man for "sucker-punching him out of the Quinjet" back in AVX, to "ALRIGHT, GROWNUPS, IT'S BEER O'CLOCK!"
Let's not forget Quentin Quire easily smitten by Lyra.
Quentin: You're from a world with no men, right? Well, I'm the greatest lover on my planet. Let's sneak away and I'll show you. Lyra:[holding Quentin off the ground by his collar] We have men on my world. We keep them as slaves. Quentin: It's official. This is the greatest day of my life.
Hawkeye and Iceman are ejected from the game for (their words) "being awesome".