K. first off. Mass Effect 2 is the best game for the 360 to date. Second, Mass Effect 2 is way better than any final fantasy game is, or can be.
Mass Effect 2 is an amazing game with great detail, characters and story lines. It wont matter too much if you havent played mass effect 1, but it would help slightly. It was designed to be a game you can play without playing the first one. It was a game that literally took up all my free time for a week once it came out. I love that game and it is most definately worth a shot. However. My advice to you is this. go to block buster, throw down $8 to rent it for 5 days and see if you like it before you open your copy up.
Man up, stand in line.