My son assumes every progagonist of every narrative he hears is a superhero using his or her powers for good. I recommend you try it.
I have been. I get to cast myself as someone brave, confident, watchful, hardworking, strong, insightfu, protective of people who need protection and worthy of respect. I get to cast myself as someone who has the necessary powers. If there is any saving to do, I have to do it myself - no one else is going to save me. I dig it.
Of course, to be true to my son's vision, I have to cast other people as superheroes as well. Which requires me seeing the mass of humanity I usually despise in a softer light. And requires me to mightily respect their choices and their powers. It's really a pretty useful way to see the world.
Much, much more useful and kinder to the pysche than the christian mythology I grew up with.
Batman, Superman, Spiderman, and The Incredibles - many for me and Owain to spend time with together. He was Superman for his first two Hallowe'ens and we go to see the kryptonite in the gems and minerals section of the Natural History Museum every time we go.
By becoming well-versed in the stories of superheroes, we have learned that sometimes superheroes do things that are bad and sometimes they do things that are good and same with the "bad guys" and the trick is to not decide that someone is bad or good in advance. The trick is to see what they do and judge what they do - why is Superman stopping that man? it's not cause he's the "bad guy", it is because he is hurting someone, or stealing something -- and not to think of people as bad or good at all. In fact, calling people bad or good is kind of a waste of time. Superheroes tend to be reasonable, which is a virtue of which I approve.
Listening to my son talk tonight, I realized heroes, superheroes and protagonists were all synonymous for him and I kinda liked it. Of course, this may be my own heroic justification for too much television.
When he was really little we did a lot with Superman. We both loved the Christopher Reeves movies (well, the first two, I find the third a little unwatchable) and really, really loved Brandon Routh in Superman Returns. (Especially because in Superman Returns, Lois Lane and Superman save each other) (and there is that killer, killer plane crash in Wrigley Field)
I would have immersed him in the important American story Star Wars before now but he insists on pronouncing it Star Whores, which would be funny if he were an ancient Hollywood agent embittered by Lucas's supremacy, but is just creepy coming out of the mouth of a five-year-old.