silver sufer's weakness is that the source of his powers is that giant planet eating dude (cant remember his name), one time all the survivors of the planet he ate, created a planet of pure darkness and disease which his new servant (some girl from earth who used to go out with torch) was dumb enough to feed him. This resulted in him almost dying and thus draining almost all of
SS's powers.
Also as he is a Marvel character he suffers from tghe some thing that every other marvel character does, a screwed up mind or some thing caused from emotions. every one had one:
Spiderman - fucked up love life (falls in love with that rich chick who becomes the black cat and falls in love with a vampire, Falls in love with MJ marries her then she turn out to be a clone, to name a few), worried about his aunt who hates spiderman, etc.
Hulk - whole thing is fucked up, in love with the daughter of the man who wants to kill him, etc.
Mr Fantastic - being the smartest bloke on the earth and having super powers, have you ever seen his ego.
Mrs Fantastic - female character from the 60's with powers of invisability and force fields, makes you think that mr ego is a wife beater and she got those powers to hide and protect herself from him.
Torch - his a teenager who bursts into flames, that can only result into trouble when he loses his virginity just imagine, "ooh baby you make me so hot......aaaahhhh"
x-men - all have their stories
Even the villains had their inner demons.
And also even with the arguments, "love" is infact a big weakness when it comes to being a superhero, to quote the green goblin from the movie "you never know when some psycho will come along with the sadistic choice"
By the way the hulk would kick supermans butt once he is mad enough.
But my fave is Gambit, i was pissed off when he wasn't in the movies.