Regeneration

Claire Bennet (Heroes)
Claire exhibits the power of rapid cell regeneration, a trait that allows her to recover from almost any injury in a matter of seconds. She also feels relatively little pain from even serious injuries, including burns and compound fractures, although she did grimace when her hand was damaged while retrieving a class ring from a running garbage disposal. She has not yet reached a limitation of her powers. Along with the injuries stated above, she suffered an injury where her neck was broken and turned around 180 degrees. This would be fatal for most humans. Indeed, between her tolerance for pain and seemingly unlimited healing potential, Claire is somewhat similar to the X-Men character Wolverine. Panettiere herself even loosely compared Claire to that same character when explaining her powers during an interview.

Apparently, Claire cannot heal an injury if a foreign object is obstructing the wound. This is true of other characters with healing factors, who can still heal incorrectly, incompletely, or not at all if certain conditions are not met, just like normal humans. For example, in the first episode, the bones of Claire's ribs were sticking out at one point. After a comment from Zach brought this to her attention, Claire had to move them around a bit before they would heal properly. The injury she received in One Giant Leap was billed by a TV Guide article as an extreme test of her powers. In this incident, she was clinically dead for hours, only to revive when the tree branch that killed her was removed. Her healing powers restored her to health despite the destructive biological processes that happen to bodies immediately upon severe trauma or death (brain death, lividity of blood in the tissues and coagulation of same, etc.). Still, as stated before, there were still limitations. Her upper torso had still been spread open from the classic "Y Incision" made in the chest of autopsy subjects and she had to close the flaps of skin back into place manually before they healed.

In Lizards, Claire cuts off her small toe with a pair of scissors only to see it grow back. This suggests that Claire is able to regrow a body part even if it is completely removed. This is later confirmed in Brother's Keeper, where she loses and entire foot and quickly regrows it.

In Kindred, Claire tells West that she does feel pain, she just recovers from it very quickly. However, in The Second Coming, Claire loses the ability to feel pain after Sylar takes her ability, though in One of Us, One of Them she appears to feel her hands burn when touching the side of the heated container.

In Cautionary Tales, it is heavily suggested that Claire's blood will heal any wound in any person if it is introduced into their system.

A painting by Isaac Mendez and Peter Petrelli showed a cheerleader's body dead at the feet of a shadowy figure, with her head sawed open and her brain removed. Once thought to be Claire, it was theorized that such an injury might well be fatal. Future Sylar was able to taken Claire's ability by telekinetically sawing her head open, and in The Second Coming, Sylar removed the top of Claire's head and stole her ability without killing her. Her skull and scalp healed as soon as Sylar put the displaced part back where it was supposed to be. Although Sylar told her that she's special and couldn't die, it's unlikely that Claire could survive complete brain removal or decapitation.

In Into Asylum, when Claire consumes a mass amount of alcohol to win a game, her competitor comments on how she doesn't even look drunk. She later admits to Nathan that her liver heals itself, resulting in everlasting sobriety.

Victor Borkowski (Marvel)
Victor has a regenerative ability that can grow replacement limbs, though the full extent of this power remains unclear. After having his right arm amputated, Victor grew a larger, scalier arm in its place.