A serious contender to the trophy of my "easiest custom ever", I'm almost weary to call it a custom. Nevertheless, I've seen some simple headswaps here, so this'll be one.

I simply took off the Dark Knight Rises Bruce Wayne and Batman heads, did a little cutting to get the head to fit (sliced a bit of Batman's neck peg, and carved a bit of the hole in Bruce's head out), then put it together. Easy as pie.