OH easily Red Steel 2 out of those choices. Complete turn around. Hell almost a different game haha. Although I enjoyed my plays of the first game, it was nowhere near an a good game and barely an average one. Especially when it came control wise, although I did like the gameplay progression in the game. Second one made it from your barely average game to a top-notch Wii exclusive.
Some of the choices up there though I'd disagree with. I think Mass Effect 2 is a downgrade from the first one haha. I also don't think KZ2 improved much on KZ1 (which isn't saying much about the second) nor do I think AC2 was a big improvement over the first (mainly because I love the first one to death). Uncharted 2 and Uncharted 1 to me are like different games but both were still solid. Really Red Steel 2 was the only good choice for me.
Other mentions would be No More Heroes 2 which made it from a good title to a wonderful one. And the most blatantly obvious one for me is Gears of War 2. First Gears of War was average at best to me, while the second one was everything the first should have been. I'm sure there are more from this gen but drawing a blank.
