In Black Lagoon, in both the Greenback Jane arc, and the Baille de la meurte. Let's face it, the fact that you can get a group of Ax-CrazyBlood Knights and Psychos For Hire in the same room and have them trying to kill the same opponent counts for this trope. The fact that so many of them live in the same city and have not turned the entire city into a battlefield is a tribute to the presiding criminal orders.
In Nodame Cantabile, the S Orchestra is made of a bunch of misfit musicians led by a perfectionist Straight Man conductor who drills into them to be more serious. But during the representation, he gives them the signal to let go and be their exuberant self... and it is awesome.
In Onegai My Melody, during the season finale, the ragtag bunch of youngsters join forces to defeat the Spirit of Dark Power. Even Kuromi the resident Anti-Villain joins, and they get a wardrobe makeover.
Done very bluntly for laughs in issue #12 of Nextwave, after the team has spent the entire time insulting and arguing with each other:
"You people will by God act like a team, or at least like people who know each other, or I'll incinerate the bunch of you here and now."
This happens big time during the Pony POV Series Wedding Arc. Chrysalis is even more dangerous than in canon and manages to brainwash Applejack and Twilight, as well as Spike and Sweetie. Who ultimately begins unraveling her plans? Twinkle Shine (a hairstylist), Minuette (a dentist and a pure good regeneration of the Master who managed to destroy his persona for good), Bon Bon (a candy maker), Lyra (a musician), and Moth (a reformed Changeling who has up until now been too terrified to act against her own kind). The not only manage to uncover something is wrong, but manage to free Moon Dancer, one of Chrysalis' slaves, and ultimately act as the Big Damn Heroes later on to save the main heroes. Also of note is Prince Blueblood, who, after a load of Character Development, is the one who saved Cadence from the mines and get her to the Wedding in time to stop it, revealing Chrysalis.
In Toy Story, it's when Woody and Buzz work together to escape Syd's yard and chase the moving van.
Alternatively, Woody rallying Syd's misfit toys to rebel and freak him out.
In A Bug's Life, Flick's defiance of Hopper's beating emboldens the ant colony to fight off the grasshopper gang.
Which, incidentally, Hopper predicted would happen.
In Toy Story 2, it begins when the toys hijack the Pizza Planet truck to chase Al and Woody.
In Finding Nemo, it's when Marlin, Dory, and Nemo organize the school of grouper fish to escape the net.
Incidentally, this was lampshaded by director Andrew Stanton in the DVD commentary, who acknowledged that Pixar loves emphasizing the theme of teamwork in the climaxes of their films.
In The Incredibles, it's when the Parrs band together against Syndrome's Mooks on the island base. Doubly impressive when you remember the kids have started being super-heroes just ten minutes ago.
In Ratatouille, it's when Remy's dad rallies the rat colony to replace the kitchen staff, who then proceed to cook dinner for a restaurant full of patrons and incapacitate two nosy humans.
In WALL•E (pictured above), it's when WALL•E, EVE, the defective robots, and the Captain all pull together to defeat AUTO's machinations and place the plant in the Holo-detector, as seen in the page image.
Happens in Mulan when Mulan and her squad infiltrate the Imperial Palace... in drag. Earlier, a smaller version of this happens as part of the Training Montage set to "I'll Make a Man Out of You".
Happens in Tangled when Maximus the stallion recruits the Pub Thugs to bust out Flynn from prison.
Films — Live-Action
In The Devil's Brigade, it's when the American hard cases (who have been baiting the Canadian elites from the very beginning) and the Canadians (who have been looking down their noses at the Americans as roughneck clods) join together to trounce the lumberjacks in the bar brawl.
The tournament montage when Team Shaolin defeats all of their opponents in Shaolin Soccer.
Happens in Sky High when Will, Layla, Warren, and the sidekicks fight Royal Pain's invasion during Homecoming.
The Fish That Saved Pittsburgh. Which is an astrology basketball movie, believe it or not
Stripes has Bill Murray give a rousing speech to his platoon that drags them out of their depression to the point where, out-of-uniform, dirty, and unshaven, they still impress the brass enough to get a plum assignment.
Red Cliff pulls off a spectacular moment when Zhou Yu and Zhuge Liang are convinced they're hopelessly outnumbered. Sun Quan reveals their allies from Shu had only pretended to defect to lull the enemy into a false sense of security. Cue the Big Damn Heroes reappearance of Liu Bei, Zhang Fei, Guan Yu and Zhao Yun fully prepared to kick ass and take names. From there, every major character proceeds to contribute a necessary element of the staggeringly epic battle that follows, including Zhou Yu's wife and Sun Quan's sister. It's worth noting that while most of these characters are traditionally seen as heroes, the movie has up until this point presented them as either too old and feeble, too young and inexperienced, and/or too suspicious of each other's motives to succeed (in comparison to the well-oiled machine of the opposing force), so "misfit" mobilization would apply to this particular interpretation of the story.
Pirates of the Caribbean had an awesome moment in At World's End, after Elizabeth's Rousing Speech, drives all the pirate crews to truly fight for their way of life. They raise their banners and prepare for the fight.
Occurs in both Deuce Bigalow movies at the climax, involving all the Abhorrent Admirers (less so in the second).
Any Given Sunday has the pre-game before the playoff game in Dallas. The Miami Sharks football team up to that point, has been a bunch of egotistical, arrogant, and flat-out psychotic douchebags. But before the game, Coach D'Amato delivers a Rousing Speech (he is played by Al Pacino, after all) where-in he simply reminds these players of their shared commitment to being the better team.
Subverted in Animal House, when Bluto gives a speech with numerous historical inaccuracies, and fails to rouse his fraternity brothers, who have given up. Finally, though, they do listen to him and create an incredibly funny end sequence.
"Was it over when the Germans bombed Pearl Harbor? Hell no!"
In The Avengers, Coulson's death was what finally brought the team together. Thor saw Coulson being stabbed as he watched helplessly. Tony knew Coulson the longest. Cap gets motivated from the blood-stained trading cards Coulson eagerly wanted him to sign. Black Widow and Hawkeye were longtime comrades with Coulson.
The last act of Kick-Ass 2, with a call to arms via social media.
In X-Men: First Class, after circumstances force them to leave the CIA facility, the kids realize that they have to get their act together and learn to use and control their powers and work as a team.
Happens in Men-At-Arms during the attack on Lord Vetinari, as the ethnically-diverse-by-decree Watch put aside their differences to catch the assassin.
Similarly, this happens in Night Watch after John Keel who's actually Sam Vimes mobilizes the Watch against the growing riots in the city.
And yet again in Thud! with the marshalling of the specials, who in this case include Vimes' own butler, the head of the thieves guild (and two body-guards), the Unseen University librarian and a (to Vimes' mind) slightly-too-keen clacks operator. This is on top of the virtually all-inclusive Watch.
Twice in Reaper Man, once when Windle Poons organises the the undead to investigate the "shop", and once when Ridcully organises the Wizards to rescue Windle Poons, although any time the wizards work together might be seen as an example.
In Robert Asprin's Phule's Company, it's the first time the company beats the "confidence course" (read that "obstacle course").
The whole final battle is this for the good-guys: Order of the Phoenix, Dumbledore's Army, teachers and staff of Hogwarts, Grawp-the-giant, thestrals and hippogriffs, centaurs, house-elves, and probably others.
In Wraith Squadron, this happens to the Wraiths when Trigit's forces find Folor Base, and is cinched by how they get out of the trap in the Doldrums system.
In The Traitor Game, it occurs when Michael and Francis finally get around to get their revenge against Shipley.
Live Action TV
Shows up in Chuck: in "Chuck Versus the Tooth", there's a scene involving former CIA agents in an insane asylum showing that they still got the stuff. Subverted as the enemy agent simply tranqs them all.
"Chuck Versus the Subway/Chuck Versus the Ring, Part II" has Ellie, shaken from witnessing her father's murder and Chuck's abduction, getting Awesome and Morgan to help her run a Pincer movement on the van holding Team Bartowski captive and succeeding.
In one episode of Farscape, the crew of Moya rob a bank to buy Dargo's son out of slavery. The main villain Scorpius has beaten them to it and is holding D'Argo's son hostage and will only release him if they give him Crichton. What do they do? They take the money from the depository and hire all the mercenaries, bounty-hunters and pirates which had been the villains of previous episodes to help them rescue him. Unfortunately, the mercenaries are either under new management, suffering debilitating health problems, on the run, or have found religion in the intervening months; even after clearing these difficulties up, it's discovered that the stolen money has been booby-trapped, leaving Moya badly burned and her crew poor all over again. At that point, Crichton gives up and surrenders to Scorpius, leaving the his friends with D'Argo's son but not much else. The mercenaries are on the point of leaving when Aeryn finally performs the Misfit Mobilization Moment by pointing out that Scorpius is using the bank as a base of operations, and offering them whatever they can find there as payment. Unfortunately, though the crew manages to escape relatively unharmed, all but one of the mercenaries are killed in the attack.
Glee in the pilot as they sing "Don't Stop Believing."
However as the club expands and the group becomes more detatched through their cliques, a major moment happens in the penultimate season 1 episode. Rachel is devastated and humiliated by being egged by their rivals, particularly as they're led by her ex-boyfriend. Jerk Jock Puck of all people rallies to her aid and gathers all the strong men in the group to help him. To add to the awesome, Camp Gay Kurt and the disabled Artie also try to help. Later the whole club bands together to do the one thing their rivals can't: perform a funk dancer number (it makes sense in context). It really signified them as True Companions.
Subverted, parodied, and generally dismantled in Misfits, particularly in the season 1 finale when it looks like the three remaining members of the highly dysfunctional Five-Man Band are finally putting aside their differences and doing something pro-active to save the others - the scene even features a Lock and Load Montage, Crowning Music of Awesome and a slow-motion Power Walk. Unfortunately, things start falling apart after about a minute and a half. Their plan is stupid and poorly executed and it fails miserably. Two members of the group are forced to leave the third behind, and then start squabbling amongst themselves until one storms off in rage, leaving the other in mortal danger. The last remaining group member does actually save the day, but only really through dumb luck, and at great personal cost.
Finally put into action in season 3 episode 4 when the timeline had been changed so that the Nazis won. They were forcing Seth, the power dealer to take powers from other people and put them into soldiers from their ranks. Curtis, Kelly, and the two Rudys save Seth by ambushing the jeep that was transporting Seth by wearing Hitler masks and shooting while unseen from the trees. When Seth gets recaptured and Curtis and Rudy captured along with him, Kelly goes to save them by herself. She takes Shaun, a Nazi officer hostage and runs into Alisha and Simon. Their reaction? "You need a hand?" Granted, it didn't go as smoothly as planned, but hey... they still did pretty well considering who they were up against and technically they still managed to save the day.
Played in Wizards of Waverly Place with Justin's delinquent class in "Everything's Rosie For Justin", when they do their wand drill. Subverted in that they all fail, because Rosie has no magic.
Also, that they all passed, because Rosie was never a wizard, and the rest of Justin's class knew what they were doing. This doubles as yet another Ass Pull to keep Justin and Alex behind in the wizard competition.
There are also several instances where Shepard has to get two people to resolve their differences.
For the final mission of Ace Combat 5, Wardog squadron prepares to attack the stronghold of the true enemy - alone. Hundreds of fighters from both warring countries converge on them, and they prepare to go down fighting. The fighters weren't there to attack them, but to join them.
Performed offscreen in Fallout: New Vegas. If you assist the Misfits in their sidequest, the effects of them banding together are summarized in the ending montage. Of course, the effects vary depending on how you helped them (giving them all a good pep talk/training session will make them successful. Giving them all Psycho/helping them cheat on their test... Not so much).
Problem Sleuth: "POSE AS A TEAM, 'CAUSE SHIT JUST GOT REAL". Then they all split up on random sidequests. Then unite and pose again. Rinse, repeat, with more flashy special effects each time.
Gunnerkrigg Court, in "Residential", when the Queslett students band together to find out where their classmates have been disappearing to—and to get some payback on the ones kidnapping them—following a plan devised by the normally-asocial Antimony.
Electric Wonderland has one in "Inevitable Christmas Adventure," as NJ, Shroomy, Aerynn, and Beatrice all head to the Cyber Middle East to rescue Trawn, and two in "LuLo," as the entire NFP staff rushes to investigate the bombing of the mall and later reports on the discovered suspect.
The Sharkasm Crew is divided up into a number of smaller crews. AMPS is infamous for talking big and losing hard. So it's a big deal when they end up in a three-way tie with the two other crews during the Paranormal Activity X tournament.
The final battle against the Brotherhood of Evil in Teen Titans. With everyone else captured, Beast Boy leads a bunch of D-listers to rescue them.
Prior to that, after the Titans East suffered a rocky start in their very first fight together (as they spent more time fighting each other), Cyborg took charge and helped them stop quarreling and start gelling as a team.
In the Futurama movie Bender's Big Score, this happens in the climactic battle against the scammers when Hermes' head is plugged directly into the battlegrid. Cue Theme Music Power-Up and much ass-kicking.
In The Substitute Autobots in Transformers Animated, consisting of Scrapper, Snarl, Wreck-Gar, and Sari. They're not hugely effective and none of them are technically Autobots, but dangit they try.
SpongeBob SquarePants - Band Geeks: Spongebob rallies Squidward's marching band. He does so by getting the band to pretend that Squidward has helped each of them individually.
The plot of the TDA special of Total Drama Island. It's oddly satisfying to see all of the show's contestants overcome their differences and come together... To bring down another show's contestants.
Seven non-superpowered Leaguers against the unstoppable, invulnerable, General Eiling in "Patriot Act" (the "Seven Soldiers of Victory" episode) on Justice League Unlimited.
The protagonists of My Little Pony: Friendship Is Magic - a librarian, a fashion designer, a weather manager, a vetrinarian, a farmer and a party planner - are hardly your first choice when you want to stop a mad goddess of the night, but they were the only ones who volunteered.