While Superman is not exactly my favorite superhero, I have watched most of the feature-films and animated movies featuring the Man of Steel himself. Man of Steel re-starts the whole story over again (unlike Superman Returns), and takes it's own style that's much different than the Christopher Reeve films.
The film starts out with several flashbacks about Clark Kent's life. Including his birth on his home-world (which he'll later learn about) Krypton which was destroyed after the planet's core was unstable. It also shows Clark's early life and personal struggles trying to cope with his abilities and trying to fit in with society. As a young man he is rather lost with no sense of purpose, and rarely uses his powers (even in a time of need) as his adoptive father feared that Earth was not ready to learn about Clark's true origin.
The film's antagonist is the ruthless Kryptonian General Zod who was sentenced to the Phantom Zone after trying to overthrow its government. When Krypton was no more, Zod broke free from the Phantom Zone but is now on a hunt for the son of Kal-El (Superman) whose father Jor-El gave his newborn son a device that could build a new Krypton. When General Zod arrives on Earth, he tries to befriend Superman, but the Man of Steel refuses after learning that General Zod plans to destroy the entire human race to make way for the new Krypton. Superman then realizes his purpose is to save the world, but his first challenge is immense as Zod and his crew all have strength that rivals Superman's.
I originally feared that Man of Steel would be disappointing after hearing mixed reviews from fans and critics. But I ended up loving it, and I personally think it's the best Superman film to date. One of the problems I've always had with Superman stories is that both the heroes and villains are rather vanilla and tame. The new film is darker, and doesn't hold back. I will have to say the final battle had too much action, but overall I can't wait for the sequel.