Need help building a gaming rig

I am looking for a new gaming desktop. I have decided to buy a pre built pc (yes yes i know building my own is way better and i am officially retarded) from cyberpower (or another suggested site). I don't know a whole lot about computers so I could really use some guidance.

My budget range is somewhere around $1500, but it is flexible. This system would be mainly for gaming but I would obviously also use it for web surfing and music. I plan on buying a monitor with probably a 1920 x 1080 resolution and at 20 something inches (any suggestions would be awesome). I am hoping to be able to play games like Skyrim on high res, also plan on getting battlefield 3 and diablo 3. As far as Intel or AMD, I don't really have a preference but from what I heard Intel is not really worth the price for gaming. Looking briefly online I was interested in something like the AMD Phenom II X6, but I am open to suggestions. I am not too interested in lots of bling and LED lights on the case but I could live with it if it was worth it under the hood.

Any help would be greatly appreciated, hopefully i have given enough information.