Originally Posted by The Question
Only Lex Luthor. I don't see a need for two villains or for a super string villain for a punch out. Lex's greatest asset is his mind, I want to see him use that to destroy Superman, not Metallo.
I feel like another villain may be needed to "show off" Batman. Lex probably won't challenge him physically and I doubt he'll go head-to-head with a full strength Superman, which leaves something to be desired to me.