A minor example, but the fact that Zach had Tom Fulp, the founder of Newgrounds voice Amy's Boyfriend is this mixed with being a heartwarming moment, considering that he's indirectly responsible for this show's existence due to him basically allowing Zach's career as an animator get off the ground.
Desmond saving Alan from the Bliblies and going on an offscreen, one-man rampage against them that ends with him killing every last one of them by himself, especially since this very act has coaxed him out of suicide and later founds a successful pest control company.
"Mr. Frog":
Glep getting the role of Mr. Frog just by spitting in Rex's face.
Mr. Frog eating Rex whole is immensely satisfying after everything the latter put poor Glep through and most likely put Frog through before.
Admit it, after all he's done, seeing Grim begging and groveling for his life while pissing himself as the Boss has him at gunpoint is o so satisfying.
"Charlie Dies and Doesn't Come Back":
Just when the Devil goes back on his promise to allow Charlie to return to Earth if he made him smile, God himself (voiced by Gilbert Gottfried) erupts into Hell and rescues Charlie before throwing him back down to Earth at his own funeral.
James, the cartoonishly evil caricature of an abusive and manipulative sociopath, and the Insane Groundbreaking Games CEO, a cartoonish but dismayingly accurate caricature of a Corrupt Corporate Executive, meet face-to-face at the end of the episode. James abruptly and effortlessly murders the CEO without even acknowledging the very real and potentially highly destructive Super-Soldier that is Troglor, and everyone is better off for it. James finally smiles, Charlie and Glep don't have to put up with James anymore, Gwimbly and Troglor bury the hatchet to join a Mascot Fighter together, and as a result, Pim and Allan's efforts to help Gwimbly pay off.
