Originally posted by Seth Gaterra:
With Superman and Luthor, Superman's thinking "we once were friends; why do we have to be enemies now?"
But this doesn't apply to the movies.
Instead, we've had Lex as an extremely jealous megalomaniac who hates the fact that Superman gets more attention than he does, and who wants to keep Supes from interfering with his real estate renovation plans.
Lex, in the movies, is an over-the-top villain in the same way the Joker is. I think that's why both villains were so effective while the villains of subsequent Superman and Batman movies lacked the same sense of power or urgency (except, arguably, the Penguin, who was grossly altered from the comics version).
So, a Superman movie villain doesn't need to have super-powers (in fact, powers could be a detriment: an excuse for special effects to overwhelm the story). Instead, the villain should challenge Superman in ways he's not used to being challenged, as Lex does through his intellect and narcissistic willingness to sacrifice billions of people.
Of the villains mentioned so far, none stands out to me as meeting this criteria, unless they are also reinvented Hollywood style.