A short list:
Kiteman, the only super-hero/villain who can be stopped by a strong gust of wind.
Asbestos man, pros - he can't catch fire, cons - he's going to die a painful death of lung cancer
Fat Man: The Human Flying Saucer, his acutal power is fairly cool he can turn into a flying saucer with the perks that entails. No, the pathetic thing is his weakness, if he sees an item of food that he would like to eat he HAS to turn back into human form so that he can eat it.
All of these actually appeared in comics.