Davy's, in the book: Scaring the terrorist who murdered his mother into surrender by dropping him off the World Trade Center - repeatedly. Also, Calling the Old Man Out. By jumping him to his mother's grave, taking the belt he used to beat him with, and forcing him to admit that his abuse tore their family apart. And not by whipping him with it, either; he smacks the ground over the grave with it, spraying grave soil all over the drunken idiot, screaming that she would still be alive if he hadn't driven her away. His father agrees, and enters AA that same day.
In the third book, Cent figures out how to more or less fly with her jumping, something neither of her parents, who have been jumping for two decades, never even thought of.
Griffin, Jamie Bell's character in the movie, was just pretty awesome overall. He...
...beat two Paladins to death with a baseball bat while they had futuristic stun-gun things.
...took the body of one to his lair & talked to it while playing videogames (Throwing the controller at it when he looses).
...steals a car & repeatedly jumps while driving, at one point driving in mid air.
...goes into super rampage mode when Roland taunts him about his dead parents, jumps so fast that he causes lots of destruction & punches Roland through a wall.
...attacks Roland with a flamethrower twice, so much that Roland actually shows fear the second time, & would have put a Nuke through the jump scar to kill all of the Paladins & got into a super cool super powered fight to the death with Davy.
...uses his teleportation power to throw larger and larger things via teleportation at Roland, at times reminiscent of Dio from JoJo's Bizarre Adventure, and culminating in a double-decker bus.
His Unstoppable Rage is Hulk-level. Just by Jumping sequentially in a straight line, he is able to generate a shock wave of compressed air that blows Roland through a wall of limestone bricks.