There are some young people who own a computer shop a short distance from where I live and they build gaming computers all the time. They are very reasonable in price also. I just go to them and have them install new components and a new Windows operating system. Trust me the young people who really know computers are the people you want building your computer. Unless you are a computer expert and can do it yourself.
Now I have never owned a gaming computer, because I never really got into a lot of computer games. Myst was own of the few I liked. But a powerful computer is useful if you want to do stuff like working on photos and videos. And you don't have to have a Top Fuel gaming computer. Heck, the very first custom built Windows computer I had built for me cost only a little more than a typical Dell and it would run circles around one of them.
I recommend however paying a little more so that you can get a really good case, good power supply, etc. A good case can last ten years. And stuff like the quality power supply, card reader, etc., can all last a long time. Other stuff needs to be replaced more often like the motherboard, processor, RAM, and graphics card. To run Windows 8 right I would need a new motherboard, RAM, graphics card and processor. But that stuff is due for replacement anyway. All of that stuff is old but still fast. Windows 8 has support for USB 3 and secure boot etc., so you need a motherboard that supports all of that. I wind up paying less for what is essentially a new computer than what people are paying for a brand new computer in a store.
I seriously recommend the custom built Windows computer to anybody considering a new computer. Just find the people who can do a good build.