What video game are you currently obsessed with?

Is there are video game right now that you are constantly playing and trying to beat or get higher scores on?

If so, what is it? Why are you obsessed with it? How long have you been playing it? Are you just trying to beat it or are you going for the highest scores/achievements? Do you think you will get there? Do you think you will ever give up or get sick of it? Do you have a great high score on an all-time, world list?

It can be any type of video game: console, on-line, iPod app, cell phone, arcade…