Anything about good going desktops?

I'm looking for a built desktop that can handle most games in high settings like just cause, Minecraft, Watch dogs, Dayz, Battlefield, Etc. I don't know much about computers, I don't know what they need or what to look for. The computer I was thinking to get was the AlienWare x51 or Vanquish II. I'm not sure which one is good at gaming? The price I'm looking for is around $800-$1,500. Please help me and explain what is important in a computer.

ALIENWARE IS OVER PRICED GARBAGE…

You'll pay extra for a cheap plastic case with lights all over it that get annoying quickly.

Build one, google "build my own gaming computer" and learn how… Its simple.

I threw this one together in about 4 minutes, its your high end price range of 1500

http://www.newegg.com/...6811139018
http://www.newegg.com/...6814121878
http://www.newegg.com/...6817139084
http://www.newegg.com/...6820231503
http://www.newegg.com/...6813131801
http://www.newegg.com/...6819116940
http://www.newegg.com/...6835181032