Fallout was fun and all, but the dismemberment was insane. Far too over the top. I just read that Bethesda was considering dismemberment for Skyrim. Do not do this please. It would look stupid. Even constant finishing moves where you decapitate would take away from the general feel immensely. When I always cut off an enemy's head and be insanely flashy with inhuman feats, I don't get nearly as into the game I'm playing. It's dehumanizing, nobody can cut off every head perfectly or blow up somebody to the extent seen in Fallout 3 every 5 seconds. It looks silly. Please don't do it. It doesn't belong in the Elder Scrolls universe.
Edit: I do mean extreme dismemberment. I realize if you're cutting with a sword, stuff can happen.