I rely on benchmarks and feedback of computers. So whichever has the best benchmarks for CPU and GPU and best feedback of positive reviews from already existing customers.
Additionally before buying any computer you will want to verify that it can do everything you need it to, such as when it comes to some games if your planning on gaming with this computer these might be too weak of CPU and GPU processing power to play specific games of choice. Additionally any specific spec features you require such as HDMI connector for displaying onto another display one computer may have while the other is lacking or you need it and suddenly realize that both of these are lacking it, to which you find yourself looking at yet a totally different computer model or models to compare against.
