At the end of Astérix and The Cauldron, the eponymous (money-filled) cauldron falls off a cliff onto the pirates' ship. The panel even has a caption reading "And for once, the pirates are happy!" (though Asterix and Obelix DID kick their asses as usual earlier in the book, albeit unjustly).
There are also a few occasions in which Cacofonix saves the day with his dreadful music, and the villagers reward him by letting him participate in the victory feast (as opposed to tying him up to prevent him from singing as per the usual Running Gag) - most notably Asterix and the Normans, where he actually gets to perform for the village with the One-Shot Character whose life he saved (although he still isn't allowed to sing). Also, when he's been having a run of especially bad luck to the point where the other characters picking on him further would make them unlikeable, they tend to let him sing as an Aww, Look! They Really Do Love Each Other moment - his usual nemesis Fulliautomatix asks him to sing for him to cheer him up in The Secret Weapon after the village women run him out of town, and in The Falling Sky, where he has had the worst luck he's ever had and ended up losing all of his possessions due to Ethnic Scrappyaliens immolating his house and then erasing everyone's memory of it, he's even allowed to sing at the banquet, even though everyone else is obviously in intense pain.
At the end of Asterix at the Olympics Games, the Romans Glutius Maxmus and Veriambitius, after spending the entire book being upstaged and humiliated by the Gauls' antics, are given the Palm of Victory Asterix won to present to Caesar. A caption reads, as Caesar rewards the Legionaries, "For once, Caesar is pleased!"
Don Rosa loved doing this to Donald. The Duck Who Never Was did it as a sixtieth birthday present to the character via It's a Wonderful Plot, while The Magnificent Seven (Minus Four) Caballeros sees Donald's foreign friends from The Three Caballeros make a return and take him on an adventure to cure his depression.
There was a brief scene in Gotham Knights where for once, Batman accepted the Spoiler, even telling her that he doesn't mind the company.
In Volume 5 of Empowered Emp (kidnapped along with a bunch of the Superhomies' celebrity doubles) wriggles out of her restraints, dons her super suit (which she'd wrapped around her waist) and tells off the double who insulted her earlier. Then for once, just once, she actually smiles in anticipation because the mooks have no idea what's coming.
The tract Stinky from Chick Tracts has a mild example: The title demon after failing his task, is seen happily slacking and relaxing at the end while his master is being punished by his boss, Satan. What makes this special is that all previous tracts ended with all the bad guys, without exception, being thrown to Hell or punished for their failure.
Because of Spider-Man's status as one the first Chew Toys of the Marvel Universe, occasionally writers will throw him a bone here and there. Such as Stan Lee giving him a motorcycle, introducing him to Mary Jane, and generally making his life better after Stan's fellow plotter Steve Ditko quit Marvel.
One of the biggest changes is in Ultimate Spider-Man where in J.Jonah Jameson stops hating Spidey and becomes pro Spider-Man! Plus he knows that he's Peter Parker and vows to never reveal his identity to anyone!
After watching over and over again as Kid-Loki tries to remember his brother—and after that have the memories but no one else does, and watch everyone call Tanarus his brother to his face while Loki's clearly getting angrier and more distraught, Loki manages to recover Mjölnir and gain his first ally in the search for his brother. Who is this ally? The Silver Surfer.
A very unintended side effect from the Screwed by the Lawyers-mandated Cosmic Retcon of Archie Comics' Sonic the Hedgehog as Sonic comes back from his adventure with Mega Man to find out Mobius has changed for the better - all the damage done by years of war against Robotnik and Eggman have been undone, the injuries and sadnesses and heartache that came from these adventures never occured. It hits home initially when he finds out that King Max Acorn isn't a massive jerk like he was in the old universe and the bones just keep being tossed at him.
At the end of The Superior Foes of Spider-Man, after being the butt of all sorts of jokes as well as the recipient of all sorts of crap, Shocker ends up defeating the Punisher in a single blow and is installed by Silvermane as the new boss of the Maggia. Similarly, Speed Demon ends up successfully suing Iron Fist for an injured ankle and also ends up wealthy.
In Booster Gold #1,000,000 (a tie-in with DC One Million), a series of events that make Booster an epic-level Butt Monkey has him quit Rip Hunter's team and halfway to retiring from heroics entirely when he gets a call from Batman. Bruce shows Booster photographs from the night Joker paralyzed Barbara Gordon, revealing that he knows Booster tried to save her (but sadly failed), and admits that he was wrong to think Booster was just a greedy idiot. He tells Booster "Let the world think you're crazy if that's what it takes to be the best you can be" and adds that if he ever needs someone to just talk to, he'll be there. Then when Booster goes back to Rip to rejoin, he finds his sister Michelle alive and well, thanks to Rip bending the rules of time travel to save her. As they leave to eat lunch, Rip smiles and says "Keep it up, Dad" quietly, and the ending narration notes that despite the fact that Booster Gold is considered the Black Sheep of the Carter family, every photograph of him shows him smiling happily.