After The Last Continent, Rincewind returns to Unseen University to a position as Egregious Professor Of Cruel and Unusual Geography and lives a life as quiet and uneventful as he can manage. It doesn't completely work (talking himself onto a space flight in The Last Hero, for instance), but his days as a Cosmic Plaything seem to be over.
The Science of Discworld trilogy makes it clear that Rincewind is still being called on by the faculty to go on missions, though they're seldom life-threatening, and he appears... well, maybe not 'enjoy them', but he actually becomes respected. In part IV, he visits modern-day Roundworld with archchancellor Henry (ex-Dean), and he treats him as an equal.
He appears briefly in Unseen Academicals, engaged in, by wizard standards, a completely mundane activity, and is never called on to do anything dangerous. His eternal wish for a life of boredom seems to have come true. He is seen preparing to attack two powerful wizards at the cusp of fighting to prevent another wizarding war the same way he ended the last one, but after things calm down everyone politely pretends they didn't notice.
Tom Holt's main characters tend to spend 99% of the book being attacked, manipulated, arrested, sued, sold, killed, brought back, hurled across the universe, turned into werewolves, killed again and vivisected. In most cases, at the end, they are duly given vast amounts of money, handed a significant area of land somewhere on the other side of the planet, and the Dark Forces of Weirdness kindly butt out of his relationship with the Love Interest. (This doesn't happen in every book, but it does seem to turn out this way more often than not).
Harry Potter: Neville Longbottom spends the first six books of the series as the sad sack of Hogwarts, being a klutz even when doing simple things like walking, being one of Snape's constant targets for abuse (second only to Harry), and only being good at one class: Herbology, one of the very few classes in Hogwarts that doesn't require magic. Finally, the stars align for him in Book 7. With Harry and the gang out of Hogwarts trying to find the horcruxes, he and Ginny and Luna lead the resistance against Snape's new regime at Hogwarts. Though he does experience his fair share of torture throughout the year, he holds strong and keeps the resistance going. But his true Crowning Moment of Awesome comes at the end of the book, when he pulls the Sword of Griffindor out of the Sorting Hat and proceeds to lop the head off of Voldemort's snake, Nagini, destroying the Dark Lord's final horcrux and making him a mere mortal once again. Talk about taking a level in badass!
There are hints before Book 7 that Neville may be something of a Crouching Moron, Hidden Badass, such as his part in the Ministry raid in book 5, where he's not the most useful by any stretch of the imagination but proves that he has Gryffindor-grade balls just by going. He's really good at herbology and also Charms, according to the book version of Half-Blood Prince, where Professor McGonagall recommends that he take a N.E.W.T in that subject... and there's that one minor thing... yes, he bears the burden of his parents' Fate Worse Than Death without collapsing himself.
Neville gets one as early as Prisoner of Azkaban, when ProfessorLupin has him help with the demonstration as to how to fight off a boggart. Not only does Lupin kick it off by telling Snape that he's sure Neville will do the job spectacularly (this being after Snape humiliates the kid by saying that Neville bungles every job given to him), but the confidence boost means that Neville is able to finish off the boggart for good at the end of the class, winning ten points for Gryffindor in the process.
Philosopher's Stone gives one to Neville and Ron both, after both tend to be overlooked and considered subpar (especially compared to students like Harry or Hermione). When Dumbledore gives out honors for saving the stone, he congratulates Ron for "the best game of chess that Hogwarts has seen in some time" and gives him fifty points to Gryffindor for it. In the midst of the cheers, Percy of all people can be heard bragging about how "my youngest brother" Ron was the one to beat the enchanted chessboard. Neville, meanwhile, was given ten points for being brave enough to stand up to his friends for what he believed to be right, thus helping Gryffindor win the House Cup (keep in mind that at the time, Neville's well-meaning actions were actually hindering the protagonist, and ended with him being frozen and left on the floor all night).
It's actually implied pretty heavily that Neville's lack of skill in magic is due to a crippling terror of Snape (in Potions, having the guy hovering over him makes him nervous and prone to screw-ups), having to use his father's wand instead of one that is better suited to him, and/or the way his grandmother always tries to make him be more like his father.
And finally, after the events of Deathly Hallows, the epilogue mentions that Neville has settled down into his one true calling: Professor of Herbology at Hogwarts. Word of God also tells us that he's Happily Married to classmate Hannah Abbott. Neville earned his happy ending, darn it!
Hannah Abbott herself started out as a relatively normal young witch that the world suddenly decided to take a dump on around Book 5. First she has a nervous breakdown during her O.W.L. exams (May-June 1996). It's never stated how many O.W.L.s she actually got, either. Then, right as Book 6 starts (September 1996), her mother is killed by the Death Eaters. She misses that entire year but is forced to go back to Hogwarts and presumably retakes sixth year in 1997, except now Hogwarts is under the de facto leadership of the wizard who caused her mother's death. She finally gets a bone thrown to her in the end - by the time of the epilogue, she eventually marries one of the biggest still-living Badasses in the entire book series and becomes the landlady of the Leaky Cauldron.
In The Pilo Family Circus, Mugabo is powerful magician reduced to the level of performing cheap tricks for the circus' audience, and occasionally being intimidated by Gonko or Kurt Pilo into pulling a rabbit out of a hat. Even his occasional breakdowns aren't taken that seriously. At the end, though, after narrowly avoiding death at the hands of Kurt Pilo Unmasked, Mugabo is finally given a chance to show off his true power to the audience: judging by the reports of a "cheerful black man shooting comets out of his hands," he had the time of his life.
In Death: Eve and Roarke certainly got this by meeting each other at the very beginning of the series. Interlude In Death even has Eve putting a Lampshade Hanging on this trope, with regards to their relationship.
In Breaking Dawn, after everything Leah does causes the other wolves to heap scorn and hatred on her, there is one shining moment where Jacob appreciates her telling off Bella and speaking in his defense. Granted Jacob doesn't think Bella deserved it and changes his mind about being impressed when he sees how upset poor little Bella is, but it's still nice while it lasts.
Swedish writer Simona Ahrnstedt does this with Beatrice, the poor female protagonist of her debut novel Íverenskommelser. Beatrice might be intelligent, competent and tough, but still, she doesn't have a good life as a girl or as a young woman. Sometimes though, she does get some nice moments in her life. She has two good friends in her cousin Sofia and their companion Mary, and she also gets a third friend (Vivienne). Beatrice's relationship with her love interest Seth is complicated to say the least, but still, it gives her some moments of joy, so that she doesn't think sex always is bad after she gets raped. And in the end, she and Seth can get married.