You shouldn't be doing either.
You should never defend your favourite. What you should do instead, is attack the opposing character or team pitted against. You have the added benefit of offending other people that way. Never, under any circumstance, attempt to defend what you've said; just attack the other person's argument over and over and over until one of you dies of old age or some legislative branch agrees to shut down the Internet forever. Defending yourself or your argument is a weak act of desperation which informs your enemy that you're completely open to attack.
Edit: before Zoltan