They are both annoying.
Obito seems to get hit by Kakashi's words more and more. His facial expression shows he tries to scream loudly so Kakashi's words do not harm him. Pretty please, not another talknojutsu victim.
Madara is cool but so far, has shown no personality at all, except for being cocky. Why does he want eternal peace and a dream where everyone is stuck? He hasn't said it. The whole 'I do it because I can' doesn't satisfy people with answers.