Whateley Universe example: Don Sebastiano, after ruling the campus for a year, got his comeuppance when his two mindslaves were freed from their magical Mind Rape. He came back from a humiliation and dunking (in the middle of winter in New Hampshire) and thought Cavalier and Skybolt were still victims. The only thing that would have been worse is if all the dorm residents who stood around and watched had thought to get photos. Then, while in the hospital, his fellow Alphas came by and laughed at his medical charts: the lamp base that had to be removed from his lower colon was a big hit.
There's another fine example in Tansy 'Solange' Walcutt, who seems to exist solely for the purpose of a Humiliation Conga. She was doing perfectly well as the Don's second - right up until she made the mistake of attacking one of the protagonists. Her downfall since then has been... protracted, even if most of it is getting hoist by her own petard and refusing to learn.
Anti Villian example, in Doctor Horrible's Sing Along Blog Dr. Horrible just humiliates Captain Hammer thoroughly instead of killing him. It might have been worse than what he was planning, because Captain Hammer has shown himself to be incredibly egotistical and narcissistic, so having everyone pay more attention to Dr. Horrible, his arch-nemesis would be pretty mind-crushing.
Red vs. Blue: When Tex is reawakened... She takesonEVERYONE. The battle is thoroughly humiliating for the Reds and Blue. There's a reason that episode is called "This one goes to eleven"...
The Nostalgia Critic gets put through one hell of a conga at the end of Kickassia. After getting firebombed in his garden and fleeing for his life (with a girly scream), Critic is cornered in his own base and learns that his subjects have turned against him—and they're being aided by the traitor he had banished. Film Brain (who has been acting as Critic's personal Yes-Man) tells him to his face that he hates his guts, while Phelous uses Critic's habit of stealing his ideas to trick him into literally inviting the group to kick his ass. Ask That Guy shows up, making Critic think he's been reprieved, only to happily leave once he gets in his obligatory "cameo appearance". The team beats Critic within an inch of his life, stripping him of his presidential hat and authority, which they then fight over with his second-in-command (who admits that she only took the job so she could murder him and claim the presidency for herself). In desperation, Critic threatens to kill himself and everyone else with the dynamite he installed under the base; he dramatically pushes the detonator...and nothing happens, because Cinema Snob disabled the explosives (after he was banished, no less). The group resumes beating Critic to a pulp (ruining his M. Bison costume in the process), and then forces him to return the country to President Kevin Baugh—with the admission that he couldn't handle the job. And in the end, he doesn't even get the rocket chair he wanted.
The ending of "A Simple Wish" review. After Nostalgia Critic constantly insulting Mara Wilson for some of the crappy movies she made as a kid, she (In character for the video) appears and admits that everyone makes mistakes when they are young. And promptly shows "Very embarrassing" home videos of Critic while belitting him. Then turns into an demon, with the words "Don't Fuck with Mara Wilson!!" appearing on the screen.
ProtonJon gets this in The Runaway Guys's LP of the Mario Party 1 board Yoshi's Tropical Island. In one turn, he gets a poison mushroom, gets warped back a few spaces, a Happening Space event results in Toad and Bowser switching places, and then Luigi and Yoshi (the former a CPU, the latter NintendoCapriSun) both get a regular mushroom from the same item space. All punctuated by him yelling "GAAAAAME!"
another one happened to Chuggaaconroy in the Mario Party 4 board Toad's Midway Madness. It Starts With ProtonJon using a magic lamp to get a star only to get another one 10 seconds later. The third Spawns Exactly where Chuggaaconroy is at this point (for the record, you have to go around again if a star ends up precisly where you are), gets his coins stolen from both ProtonJon and the AI. All in a single turn.