If you're a huge nerd like me, then you'll most definitely want to play the first one before you play the second. The games play like an interactive movie, and even though the stories are independent of each other, I think the overall experience will be a lot more rewarding since you'll appreciate all the positive changes better. If you play the second one first, you won't enjoy the first one as much. See what I mean? It's really up to you though.