Personally, Superman is my least favorite superhero ever. I'll tell you why.
He thinks we're weak.
Almost every other superhero there's ever been started as a regular old human, and they were given super powers later in life somehow. Their secret identity is their super powers.
But Superman was BORN with "super powers." He has always been Superman, even if he didn't know it for awhile. His secret identity is Clark Kent. He hides among us, thinking the best way to hide is to act weak, skittish, shy, and clumsy - because thats how he sees us compared to him. It's degrading.
Personally I take Superman as an insult to our species, calling us weak and that we cannot help ourselves.