In Animorphs, because the kids can morph or demorph to heal all bodily injuries, it takes a lot to kill them. Typical battles include at least minor injuries. More commonly the kids suffer major injuries; arms being cut off, major blood loss, et cetera.
In the second last book, when Jake, woozy from blood loss, gets shot in the head by a human-Controller. Miraculously he survives long enough to demorph.
Bear-Rachel getting an arm cut off and using it as a weapon also qualifies as memorable.
Also, after reassuming the original form, the morpher's bodily injuries could theoretically be healed. In Megamorphs 2, Tobias says that he should be able to heal his broken wing after morphing and demorphing. Ergo, any bodily injury sustained in the original form of the morpher should be repaired, including brain damage, amputation and the like. Age would remain unaffected as DNA degrades with age: a newborn cloned from a 27-year-old's cells will essentially start with 27-year-old DNA and cells.
James, The Leader of the Auxiliary Animorphs, is crippled due to an accident rather than a genetic disease, so after demorphing from pigeon he finds that he can walk again. Similarly, Loren's blindness is cured by morphing. Marco also heals a dog bite by morphing then demorphing.
In the Sword of Truth, the hero Richard rips out his evil half-brother's spine, but he's still good for one last fight. It's played completely straight, and made even more ridiculous when it's revealed the character had no superhuman or magical abilities (though he did have some kind of funky acupuncture/acupressure technique that he somehow used on himself in order to keep going).
In Steven Erikson's Malazan Book of the Fallen, ultra Bad Ass Karsa Orlong has one of these. In The Bonehunters (book 6), he gets repeatedly mauled, cut, stabbed and bitten by a giant monster, and ultimately walks away with a slight wince and the scowl he always wears. This is somewhat justified by Karsa's being far more than a mortal human.
In Consider Phlebas by Iain M. Banks, the Idirans are revealed to be incredibly resilient to damage. One member of the species is apparently killed, and a fairly sensible member of the protagonist's crew decides to make sure of it by putting the barrel of his laser rifle into the Idiran's eye and torching off a good portion of its head. Turns out that this isn't nearly enough to keep an Idiran down, leading to the book's eventual Downer Ending.
Harry Potter: Quidditch is a sport that involves heavy iron balls knocking people off broomsticks 50 feet in the air and it's specifically mentioned that the worst injuries players have suffered (at Hogwarts) are broken bones. When Harry asks him if anyone's ever died playing Quidditch, Wood responds, "Never at Hogwarts", which seems to imply that fatalities have occurred elsewhere.
It's a more minor example than most of these, but the four Aurek Seven stormtroopers in Survivor's Quest should count. Two of them fight for and protect two unarmored officers against a large number of Vagaari armed with blasters and charrics. Their armor is good, the blasters are fifty years old and have a weak charge, and charrics aren't designed to pierce this armor, but there are a lot of Vagaari. By the time the other two show up it is mentioned that their chestplates aren't white anymore, they're having trouble standing and walking, the nonhuman stormtrooper is forgetting to translate his responses to commands into Basic, and the other isn't responding at all, and yet they're still shooting, still taking the blaster bolt. That's how Zahn writes stormtroopers. They take a lot of damage, shoot well, and never give up.
Harry Dresden. Seriously. In Fool Moon alone, he gets chin-decked, shot in the shoulder, pistol-whipped, beaten with a tire-iron, slammed into various walls, savaged by a werewolf, knocked out by overuse of magic, stomped to a pulp, duct-taped to a pillar from which he rips himself free, tossed over a wall, dropped out of a moving car on the Interstate, and tossed down into a 20-foot pit, yet still manages to use powerful magic, climb hand-over-hand up a 20-foot rope, and otherwise kick the living shit out of the bad guy by the end. His friend Murphy also somehow manages to climb up a rope and rapid-fire a .38 mere hours after sustaining a compound fracture to her right arm. And that's just in Book 2!
To be fair, Harry Dresden is a wizard, and a lot of his abilities to take damage and keep going are quite literally A Wizard Did It. He actually uses pain to fuel magic. In addition, unlike many examples here, Dresden does show his injuries, even if they aren't as prominent as they should be. He's abilities fade as he gets hurt, many of the book's climaxes find him completely drained and throwing around magic that wouldn't disturb a fly, and the epilogues are mostly Dresden lying around for weeks while all his friends come by to both inform him of the results of his actions, and to make fun of him for being a pansy.
Dresden's medical examiner friend Waldo Butters believes that wizards are capable of healing any injuries completely, given enough time, and this is also why wizards live for hundreds of years. Of note is a severe burn that crippled one of Dresden's hands. Several books later it is almost normal.
Woodrow Lowe from Man of the Century by James Thayer. In the course of the book, Woodrow is whipped raw by dervishes, bloodied by a sadistic lover, knocked off a boat by an incoming boom, kicked by a horse, trampled by a bull, stabbed within an inch of his life more than once, shot multiple times, some very close to the head, has the snot beaten out of him by at least five famous 19th-century prizefighters, and is imprisoned for 368 days in a Chinese torture pit. He is a Dakotan cavalryman, a Rough Rider, an opium trader, the (deposed) ruler of China, an Amazonian sex slave, and the assassin of Archduke Franz Ferdinand. And he lives to tell about it all. At the ripe old age of 108.
In R.A. Salvatore's The Legend of Drizzt, the Companions of the Hall sometimes seem to be made of iron. For example, in The Halfling's Gem, the five of them take on an army of wererats, a hydra, get sent to Tartarus where they're swarmed by demons, Drizzt has the fight of his life against an opponent who is his equal... and when it's all said and done they have not only managed to beat all of the bad guys, not only managed to survive, but none of them are even seriously injured. And even though they're kind of tired, you get the sense that they could have kept on fighting for another few hours if they had to.
justified, since the books are based on 2nd edition D&D mechanics. they're all mid to high level characters, and the level of durability and endurance they show is merely what is to be expected from heroes of their caliber.
But the life in me was stronger than the life in common folk, for it partakes of the essence of the forces that seethe in the black gulfs beyond mortal ken.
In the same story, Conan himself not only survives being crucified, but after his cross is chopped down (with him still nailed to it) he helps pull the nails out and rides 10 miles before his injuries are treated.
Downplayed in Harald. The Badass Grandpa protagonist is on the run from The King's Wolves, and has been playing Guile Hero to avoid fighting them. They catch him while he's fleeing on horseback, he kills several of them, gets hit by a couple Annoying Arrows and shrugs them off - and then one of them whacks him in the head, he passes out, gets rescued by Those TwoAction Girls and spends months recovering from all of his injuries.
Lampshaded in Gilded Latten Bones, with Morley Dotes' stab wounds. The healer who treats him is astounded by the fact that none of the attacker's strikes had damaged vital organs or major arteries. Subverted in that Morley is laid up far longer than Garrett anticipated; played straight in that by all logic, he should've been one dead half-elf.
In Gesta Danorum, Bjorn "Ironside" Ragnarsson receives his nickname after fighting in a single combat against a superior number of Swedish champions, and coming out both victorious and unhurt, which is attributed to the "strength of his sides" (which are supposedly hard as iron).
The Exile's Violin: Averted. Jacquie gets bruised, splinters, hurt by the loud noise of cannon fire, etc. However, After she is tortued via regular beatings for several days she is back on her feet at full capacity quickly.