Last week, DC Comics published Superman #2. (I think this may be the fourth time they've published a Superman #2, but that's irrelevant for what I want to discuss.) In the current storyline, Superman and Lois Lane are married and have been in hiding in a new version of the universe for many years. The Superman intrinsic to that universe just died, so the Superman we've known about since the mid-1980s has decided to reveal himself to the world.
One issue he and Lois are dealing with, though, is that they have a son, Jonathan, who is starting to develop his powers. He wants to help his dad, but he's unsure of himself, and his parents want to keep him safe.
Anyway, in the panels presented, Superman explains to his son what it means to be Superman. I'll quote:
"I'm afraid someday soon -- too soon -- you will have to pick it up and embrace the 'S' for yourself. It's not about our powers, or strength, or heat vision. It's about character. It means doing the right thing when no one else will, even when you're scared…even when you think no one is looking."
I loved this. For me, it encapsulates exactly what being Superman is all about, and why I've loved the character since childhood and still buy Superman comics today.