Superman sees himself as an Earth man. (“It was Krypton that made me Superman, but it was the Earth that made me human!” he reflects in one story.) Superman is not invincible, there are limits to his power, and his enemies are about as powerful as he is. Lois Lane knows that Clark Kent is Superman, and she is a bit of an action hero in her own right.
All of these things are essential to modern Superman storytelling. Man of Steel is the first live action Superman movie to feature them. It shows us young Clark Kent as an immigrant growing up in a small town, walking the Earth, seeking America’s approval, and defending the world from war criminals who try to recruit him. It borrows ideas from celebrated Superman comic writers like John Byrne, Geoff Johns, and J. Michael Straczynski. It has a majestic musical score by Hans Zimmer. Its action scenes are some of the best of 2013, with an escape from the villain’s spaceship as the standout.
General Zod is an incredible villain, motivated as much by the welfare of his people as any personal grudge with the House of El. His army of Phantom Zone criminals is both terrifying and sympathetic, since they are fighting for a homeland. Instead of having Superman solve every problem by himself, the movie also showcases the heroism of ordinary people, with scientists, reporters, and soldiers all sacrificing and struggling to protect their world from invasion.
Many detractors of this film claim that Superman is responsible for the deaths of innocent bystanders. This is untrue. Superman does destroy a fair bit of property in this film, but we never see anyone getting hurt by this (the sequel does show people getting hurt during the fight in a flashback to this movie, because it gives in to pressure from this film's detractors).
The only problem with the film is some of its characterization of Clark’s adoptive father Jonathan. Jonathan Kent's decision to ambiguously forbid his son from saving people is unfortunate and he dies a foolish death.
This is not the best Superman movie ever (that would be Superman vs. The Elite) but it’s a close second.