Build Me a $2000 Gaming PC with OS! Please?

Solution
You don't know the actual FPS until the physical unit comes.

@fillip: The fan could be better. Like a H100i. And also, make the RAM cheaper to fit into the budget. But otherwise, looks pretty nice except for the lack of RAM.

And this would be a better rig since I'll make it a compromise for fillip and my rig.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($338.99 @ NCIX US)
CPU Cooler: Corsair H100i 77.0 CFM Liquid CPU Cooler ($99.95 @ Amazon)
Motherboard: ECS Z97-MACHINE ATX LGA1150 Motherboard ($91.99 @ Newegg)
Memory: Crucial Ballistix Sport 16GB (2 x 8GB) DDR3-1600 Memory ($139.99 @ Micro...

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There are isolated instances when the i7 will be better for heavily threaded games that actually benefit from hyper-threading. I have read and seen some semi-convincing evidence that having an i7 improves Crysis 3 minimum frame rates when running on super high-end systems.

But yes, in the majority of scenarios the i5 equals the i7 for gaming. I can say quite confidently you would be happy with either, considering an overclocked i5 can run high end multi-sli / crossfire systems.

The i5 have plenty of juice, there are probably literally 4-5 games on the market that benefit from hyperthreading, and the difference is so minute it's hardly measureable.
 
Do you also need to record? Or how about video editing?

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($279.99 @ Micro Center)
CPU Cooler: Corsair H100i 77.0 CFM Liquid CPU Cooler ($99.95 @ Amazon)
Motherboard: ECS Z97-MACHINE ATX LGA1150 Motherboard ($91.99 @ Newegg)
Memory: Crucial Ballistix Sport 16GB (2 x 8GB) DDR3-1600 Memory ($139.99 @ Micro Center)
Storage: Crucial M500 240GB 2.5" Solid State Drive ($109.99 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($55.98 @ OutletPC)
Video Card: Gigabyte GeForce GTX 780 Ti 3GB WINDFORCE Video Card ($665.91 @ Newegg)
Case: Corsair 760T Black ATX Full Tower Case ($129.99 @ Micro Center)
Power Supply: Corsair 1200W 80+ Platinum Certified Fully-Modular ATX Power Supply ($259.99 @ NCIX US)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.98 @ OutletPC)
Total: $1923.76
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-08-09 23:07 EDT-0400
 
This is a strong 1440p gaming build:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($338.99 @ NCIX US)
CPU Cooler: Cooler Master Seidon 240M 86.2 CFM Liquid CPU Cooler ($59.99 @ Newegg)
Motherboard: Gigabyte GA-Z97X-Gaming GT ATX LGA1150 Motherboard ($193.99 @ Newegg)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-2133 Memory ($76.50 @ Newegg)
Storage: PNY Optima 240GB 2.5" Solid State Drive ($109.99 @ Amazon)
Storage: Seagate Barracuda 3TB 3.5" 7200RPM Internal Hard Drive ($99.99 @ NCIX US)
Video Card: Asus Radeon R9 290 4GB DirectCU II Video Card (2-Way CrossFire) ($369.99 @ Amazon)
Video Card: Asus Radeon R9 290 4GB DirectCU II Video Card (2-Way CrossFire) ($369.99 @ Amazon)
Case: NZXT Phantom (Black) ATX Full Tower Case ($119.99 @ Amazon)
Power Supply: EVGA 1000W 80+ Gold Certified Fully-Modular ATX Power Supply ($119.99 @ Newegg)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer ($14.99 @ Newegg)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($102.98 @ Newegg)
Total: $1955.38
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-08-09 23:45 EDT-0400
 
You don't know the actual FPS until the physical unit comes.

@fillip: The fan could be better. Like a H100i. And also, make the RAM cheaper to fit into the budget. But otherwise, looks pretty nice except for the lack of RAM.

And this would be a better rig since I'll make it a compromise for fillip and my rig.
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($338.99 @ NCIX US)
CPU Cooler: Corsair H100i 77.0 CFM Liquid CPU Cooler ($99.95 @ Amazon)
Motherboard: ECS Z97-MACHINE ATX LGA1150 Motherboard ($91.99 @ Newegg)
Memory: Crucial Ballistix Sport 16GB (2 x 8GB) DDR3-1600 Memory ($139.99 @ Micro Center)
Storage: Crucial M500 240GB 2.5" Solid State Drive ($109.99 @ Amazon)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($55.98 @ OutletPC)
Video Card: Asus Radeon R9 290 4GB DirectCU II Video Card (2-Way CrossFire) ($369.99 @ Amazon)
Video Card: Asus Radeon R9 290 4GB DirectCU II Video Card (2-Way CrossFire) ($369.99 @ Amazon)
Case: Corsair 230T Windowed-BLUE ATX Mid Tower Case ($79.99 @ Amazon)
Power Supply: Corsair 1200W 80+ Platinum Certified Fully-Modular ATX Power Supply ($259.99 @ NCIX US)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.98 @ OutletPC)
Total: $2006.83
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-08-09 23:59 EDT-0400
 
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