He became one among many, but remained forever unique...
To me, this more accurately describes every Green Lantern. The concept of GL and the GL Corps exemplifies the notion that the powers don’t make the hero.
There’s many ways of proving this, but I’d like to limit this post to a look at how some of the more prominent emerald warriors view sacrifice and self-sacrifice.
Kyle Rayner is the Buddhist guru of self-sacrifice. On more than one occasion, he has volunteered to make the ultimate sacrifice – most recently during Blackest Night. Kyle doesn’t hesitate to make such decisions, because he’s content with no longer living as long as his friends survive (to fight another day). He wasn't Ion for nothing.
Hal Jordan views self-sacrifice as part of his duty. Only after Kyle was able to reason with Hal (as Parallax) during Final Night* and appeal to his sense of heroic duty, did Hal help defeat the sun-eater.
John Stewart sees self-sacrifice as a form of redemption and as making a difference. With his Darkstar exo-suit torn to shreds and being essentially powerless, John took on Grayven (Darkseid’s kid) to help Kyle. This sacrifice left him paralyzed for quite a while.
Guy Gardner views self-sacrifice as a way to validate the sacrifices of others. Guy loves his friends and comrades – he really couldn’t stand it if the sacrifice of a friend turned out to be in vain. To Guy, sacrifice has to mean something and may use it as a ‘karmic comeuppance’ for any villain who disrupts his life, which has been disrupted many times before. Guy's self-sacrificial streak can be surprising to those who only known as the once obnoxious GL.
Alan Scott isn’t a member of the corps and in this distinction we find his take on sacrifice. Unlike Hal, he doesn’t see sacrifice as part of his (formal) duty, but as an example to be set. Alan realizes that any sacrifice he makes can (and will) inspire other heroes to do the same during our darkest hour. I guess it’s a golden age heroic ethic.
The powers don’t make the Emerald Warrior...
* Blackest Night? Final Night? What is it with DC and darkness?