Re: Worst. Hero. Ever.
Powers are one criteria. I know I would rather read about Spider-Man instead of some poor mutant whose only power is that he can make his farts smell like cinnamon toast. (comparison courtesy my brother, whom I beleive originated such a comparison, but I could be wrong.)
I suspect that for many of us, we get turned off of a superhero because of one particular writer: especially when we are just starting with the hero. If I started reading Marvel Comics with Civil War, I would be turned off of the Marvel Universe as a whole because of Millar's work.
Yeah. Soimetimes a seemingly bad idea can be made into something great, like Tom Strong (I have not read it, but I figure that it's a fair assumption to make). It's all a matter of the writing and the execution. The Android Captain Marvel did have some potential according to some folks, despite being one of the silliest ideas to tarnish comic book pages. However, the imaginative concept was met by rather unimaginative writing, and that's why the comics ultimately shared a certain quality with road-killed skunks.