Super Mario.
…and my dad.
FDR, because as a child I aspired to be POTUS, and he was in a wheelchair, like me.
I have not outgrown my childhood hero, he’s the same hero I have today. A voice of reason, someone to emulate, to look up to. I’m talking about Bart Simpson, of course.
Frank Lloyd Wright.
Hehe, same! Except that I was the smallest in whatever school I was in until I hit puberty, so I carried the dream a little longer. 
I also had some kind of mental crush on President Carter. I don’t think that one ever really faded 
Duncan Renaldo
Madonna, and then a little bit later she shared the “childhood hero” title with Michael Jackson. It makes me sound like I grew up in the 80s but I was born in 1990.
Isaac Asimov. I read everything I could find by him, fiction and non-fiction. I loved how in love with learning he was, how broad his interests and enthusiasms were. He died when I was in my early twenties and it was the first celebrity death that brought me to tears.
My father.
Jim Henson and Shel Silverstein. I know nothing about them, but their wonderful work lives on, making the lives of children so much richer for it.
John Fitzgerald Kennedy.
My grandad and Bart Starr.
Equal parts Neil Armstrong, and my father.
Carl Sagan.
Although I think it was a bit more of a crush than hero worship. But he’s the closest I came to having a hero.
Batman
Popeye the Sailor. 
I had a rich imagination.
Closest I had growing up was Marty Stouffer. I loved his documentaries. Can still hear the tagline to this day: “Enjoy … our … Wild … America.”
My childhood hero wrote the first science fiction I ever read, taught me science, mathematics, psychology, history and philosophy. He taught me more about the Bible then all the preachers before and after him, and taught me the joy of the dirty limerick. I was lucky enough to meet him once when I was an adult and he was all that and more.
*In memory yet green, in joy still felt,
The scenes of life rise sharply into view.
We triumph; Life's disasters are undealt,
And while all else is old, the world is new.*
-Isaac Asimov
Maury Wills, shortstop for the Dodgers in the 60’s. I’ve had the chance to meet him a few times, and he is a classy guy.
It about killed me when he later had an ‘epic fail’ as a manager for the Mariners.