During the Princes of Darkness arc, Stargirl and Billy Batson find the dying body of Alan Scott. They encounter the Shade, who is somewhat reluctant to help. Stargirl (a teenage girl with no powers outside of an energy belt and energy staff) browbeats the Shade (one of the most powerful and longest-lasting DC villains) into helping them out. He's clearly impressed.
In the same arc, Alan Scott returning to the Green Lantern name and ending the shadow threat, saving his son in the process.
Sand's heroic sacrifice to hold he Earth together.
Also, Hector Hall's finally gaining confidence in himself, making a badass entry that even Mordru has to compliment.
The second Hourman sacrifices himself in the place of the first (while the third, his son, tries to make his own sacrifice).
Nathan Heywood's second issue, in which he gains his superpowers by saving his few remaining relatives from a metal villain by stabbing him in the throat. With a broken crutch. Mid-gloat.
In the Underworld Unleashed crossover, Alan Scott's wife sold her soul for youth. He entered Hell to retrieve it, and in the process, exorcised some of the souls in the Forest of Suicide. It works like this: his old enemy Blackbriar Thorn controlled those souls, who are transformed into trees by their sin. Scott saves said souls by refusing to break out of their embrace, despite no longer having a weakness to wood, as doing so would be like tearing their arms out. The fact someone still cares about them, even in that position, is enough for the spirits to be freed.