I worry (not fixate) on screen quality and battery cycles because I am a designer. I need to have the best quality screen because I'm looking at it all day, and I also need to make sure the output matches reasonably matches what I'm seeing. I worry about battery cycles because I'm constantly taking it on the road - charging and recharging. I don't want to go to a client meeting and have to worry about having to plug my machine in.
And for what it's worth, I don't play game on my computer. I use it to make money and to procrastinate on MacRumors.