A lot of people are making the claim that Clark had no other option at the end of the movie -- he had to kill.
I don't think that's true, in fact I think there are many different courses of action that could have been taken believably.
The best example I have is instead of Clark snapping Zod's neck, he flys with Zod as far away from Zod as possible. Going further and further into deep space, finding a sun taht would weaken them both and heading toward it. Clark's plan is to leave Zod stranded on a planet, ala Khan from Star Trek.
Originally I thought Superman could just throw Zod onto the planet and come back, but an even better idea is Clark thinking he was going to die, and willing to do so to save the people of earth without killing. Then, as he has been on earth for 33 years soaking up yellow sun energy, he has reserve energy he isn't aware of and is able to come back.
I think that would have been a much more powerful ending...showing him being the hero he is famous as being.
Does anyone have ideas for different alternate endings that they think may have worked, that do not involve killing?