I've heard great things about this game, but I never finished the first one. It was awesome at first but just felt like work to me about halfway through. From what I've heard they fixed a lot of the problems in the first one in this one so I want to give it a shot.
Here's my question though: should I finish the first before playing AC2? I'm not sure how much the storyline affects the game, and if I'll be missing a lot by just jumping right into AC2.