Ninjaed! Yeah I was thinking that when I saw this thread.zala-taichou said:A Balrog. A demon from the ancient world.
There is an abundance of Zelda bosses though. I'd either pick Dodongo (as long as it doesn't roll around or get any grenades throw into it's mouth) or that bull like boss from Majora's Mask that's really fast and 'lays bombs'.