Doom of course.
The others are OK ideas but Doom is iconic and sticks with the psyche. Between the books and cartoons, people remember him. It is unfortunate that he has never been represented in film.
No. He has not. The movies showed only a weak Lex clone. Also, in reference to the revered Anubis' Lex Love: No disrespect but Lex is nothing compared to Doom.
"Ooooh my hair fell out! Now I hate Superman!" VERSUS "Authority figures murdered my parents. I will become the ultimate authority!"