im wondering the same thing.

what would your budget be?

Theres a bunch of videos on youtube. If you type in like "best gaming pc build for _____dollars there will be atleast 10 videos for whatever budget

You could build or get a custom PC built for you for between $1200-$1500 depending on your budget or requirements. When planning your PC things to take into consideration are Graphics Cards (GPU), Processor (CPU), Cooling, Storage and RAM. Your GPU and your CPU are the two main components of the PC because they're going to be handling the highly demanding tasks which occur while gaming.

For a $1300 Gaming PC look at:
CPU: Intel Core i7-2600k
GPU: GTX 670 OC Editing
CPU Cooler: Hyper 212 EVO
Storage: At least a 1TB SATA HDD
Case: This is really your decision but one thing you really need to take into consideration is airflow and size.
PSU (Power Supply): 750W PSU
RAM: Corsair Vengeance 8GB DDR3
Optical Drive: At least a DVD Burner or a Blu-Ray reader/writer.

If you need more help I will happily answer any questions you have.

You recommended a great system but wouldn't you think for a guy on a budget wouldn't the 2500k be enough. Also the 2500k performs the same as the 2600k in all games and is better in most considering some games dislike hyper threading which is the only thing it has. I would get a 2550k though since the only difference is that it doesn't have the on board graphics which in the end, a pc gamer will have a dedicated card. And thus not having the on-chip graphics there will be less heat generated.

Graphics Card : GTX 690

Before going on Newegg and looking at the highest price item, read the thread man. He said he doesn't want to spend $2000, the GTX 690 is alone $1000....