Heavenly Sword had fantastic voice acting :) The acting in mass effect was good but some characters just felt entirely too dull.
I think Metal Gear series has phenomenal voice acting :P It matches Kojima's narrative style almost perfectly, David's voice works well for snake, and some of the villains deliver on the emotion so perfectly. And content for quality, theres almost no better in my opinion. When I hear the acting, and see the cutscenes, everything fits. Of course he mumbles, he's a dog of war with a smoking problem that enjoys spending time in boxes. End of discussion XD
It's the same way I feel about Uncharted, the dialog was a little cheesy, and for the direction of the game, I feel it was supposed to be, it had a very quaint feel to it and it worked out perfectly for the title.
I will give the title to Heavenly sword though because it delivered on so many different levels of emotional range, and all of them were coined perfectly :) Bohan was hysterical, Kai sounded crazy :P, and Nariko was absolutely passionate.