I recommend building your own, the parts are much cheaper and you save TONS of money. I spent 2700 dollars on parts (thanks parents) and I havn't found anything I can't run with everything maxed yet, with tons of fps.
The point is- you can spend very little money and get a great cpu that can run everything. You don't have to spend nearly as much as I did and you'll still be fine. The most important is memory, graphics card, processor. (However that doesn't mean you can skimp on the rest neccecarily.
Edit: Mine is a desktop so the prices/function may vary. I havn't gone into detail of ever purchasing a gaming laptop.