It depends on the context. Love reading about Wolverine. And Hugh Jackman! Yum! But his powers, not that great. Beast, he's just awesome. But Kelsey Klutz Grammar....Not how I pictured him. In almost all adaptations I like Superman, but he is a little squeaky clean.
I always said Batman....cause, he's a self-made superhero. He decided he wanted to be a superhero, he didn't have any super powers....but, he didn't let that stop him!!! He worked at it, and became one.
Spiderman....got bite by a spider, big whoop.
Wonderwoman... another alien.
Hulk...scientist who gets his kicks by experimenting on himself...not such a smart scientist, eh?
Batman in truth is not a "Super Hero" as he has no super powers. Superman is the original but did not live up to his potential and the stories got stupid. Spiderman is cool, a teenager, always in trouble with one thing or another, but totally understands what it means to have great powers. Spiderman is now my favorite comic book super hero. For non-super powered heroes, it's got to be Batman. And Batman just isn't right without Robin by his side. Robin is very cool
Sandman? Worst hero? Well yeah, I'd say he is a really bad hero, because he is a villian. He was a hero briefly, but that did not last.
Now if you are talking about the DC comics Sandman, that's a different story. Neil Gaiman's Sandman is awesome, though not a superhero. The Golden Age Sandman, Wesley Dodds is cool in his own right, but he is more in the Batman vein.
BTW Wonder Woman, not an alien. She is an Amazon. They come from Earth. She might be an illegal alien though. I'm not sure if she has US citizenship.
As far as best superhero, I'll have to consider it and post later.