Worst super hero? Pretty much any character inspired to fight crime by a hero that clearly doesn't need any help from them. There are plenty to choose from, but the worst offender has to be 'Bat-Mite'.
Now, pretty much everyone knows that Batman is a guy that relies on his appearance to strike terror into the hearts of villains.
Why then, does one of DC's most feared and capable heroes allow himself to be stalked by an interdimensional imp in some random kid's Halloween costume (then again, it is quite worrying that Batman likes to hang out with a half naked teenage boy, whose get-up is surely more appropriate for hitting the gay bars on the weekend than a spot of crime-fighting)?
If I was Batman, I would've given Bat-Mite a swift, brutal and bloody bat-asskicking straight back to his home dimension.
Don't get me started on Ace the Bat-hound and Krypto the super-dog....