Who do you think would be second best choice to play the Joker in the next Batman movie?

No one can replace Heath Ledger, that was HIS character, HE reinvented the Joker. Ledger literally lived in a hotel room alone for a month formulating the character's posture, voice and psychology, and kept a diary, in which he recorded the Joker's thoughts and feelings to guide him. Anyone else trying to duplicate that performance would just be a imitator or ripoff.