When I look for any new device, including computers, I look at the reasons why I want to purchase it in the first place. If I am a gamer, than I am going to need to base my purchase off of that criteria, or if I am wanting to use a computer for work-related activities, I'd do research into that, and get the best operating system for those tasks.
Price is one of the first things I consider. The amount of storage on the computer and the speed are important to me. I am researching right now for a new computer, I like the hp products and will probably stay with hp.
As opposed to the majority of people here, my choices are based on simple aspects. If it doesn't overheat and lasts for more than 5 hours - in case I choose a laptop -, then I buy it. And I make sure it doesn't go over a few hundred dollars. I don't need those latest shiny graphics cards and I7 processors... I use my current desktop PC only to communicate with y'all on forums and other sites anyway!