I'll have to place my "vote" on Lich King.
That's just wrong in my opinion just because he is not the last boss expansion doesn't mean he is automatically weaker than the last boss of the expansion. For example, look at Wotlk most of us and everyone know that Yogg saron is 10000000 times stronger than the Lich king and what we fought in Ulduar wasn't even his full strength.
In topic: I think it will be a close fight but the Lich King will win.
Last edited by Velshin; 2013-05-07 at 11:50 PM.