When my son was four, he told me about Batman. He had learned about the superhero from his friends at school and was brimming with the type of facts that get garbled up when children try to teach each other information.
My son loved Batman and wanted all things caped crusader. We eventually got him some books on Batman and some shirts (so many shirts!) then finally let him watch some of the shows made for younger children. Everything was in moderation (at least on our end).
Batman was the first really big thing that my son got into, but my husband and I tried to proceed with caution - superhero stuff is usually way too violent for the preschool set. A researcher (who was previously able to draw a link between the unhealthy effects of princesses on preschoolers) has found that the moral themes of most superhero programming goes over younger children's heads. The part that sticks, unfortunately, is the violence.
When we were at the height of my son's Batman obsession, I admit to trying to get him to love my favorite superhero instead (Peter Parker is a model teenager who maintains good grades, helps his aunt and still saves the world as Spiderman), but my son saw straight through my ruse: For him it was all Batman all the time.
Of course, his love of Batman has faded over time. And, admittedly, I miss the Batman phase. Especially since my son is currently obsessed with Pokemon.
What was your child's first favorite superhero? Share with me in the comments.