The ending of the Pulp Fiction episode, when Pumpkin and Honeybunny decide to rob the diner because it cuts down on 'the hero factor'... only to discover SupermanandBatmansitting in the very next booth.
During the cornucopia bloodbath: "District 9 has found the mecha!"
Dutch from Predator appears very filthy in "How To Survive An Alien Attack," explaining that after he sets up booby traps for aliens, he likes to hide in the mud and watch the aliens get trapped.
Interviewer: That doesn't smell like mud.
Schaeffer:You don't smell like mud!
Megatron constantly interrupting his Battleship game with Optimus Prime to express his inability to accept the existence of a movie based on the simple game. The last straw for Optimus comes when Megatron points out that Battleship even stars Rihanna, and sings, "You sank my ship in a hopeless place!"
After Tony asks Superman and Batman if they feel jealous about how epically he and the other Avengers managed to save the world from Loki:
Batman: I'm not jealous. I'm Batman.
Superman: I guess I would be jealous, if I wasn't like all of you combined! If I couldn't fly, or shoot lasers, or catch missiles, or see really far, or smash through buildings, or wear red and blue...
(large piles of money suddenly appear)
Tony: What's that? You're fading out.
Steve: Whoa! We've broken too many records!
Thor: We can't hear you through all of this box office money!
(The Avengers laugh as the money pile grows so large, everyone gets buried except for Batman and Supes.)