Getting a new PC .

part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($189.99 @ Microcenter)
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler ($19.99 @ Newegg)
Motherboard: Gigabyte GA-Z77X-D3H ATX LGA1155 Motherboard ($109.99 @ Newegg)
Memory: Crucial Ballistix Smart Tracer 8GB (2 x 4GB) DDR3-1600 Memory ($79.99 @ NCIX US)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($69.98 @ SuperBiiz)
Video Card: Sapphire Radeon HD 7950 3GB Video Card ($289.99 @ Newegg)
Case: Antec Three Hundred Illusion ATX Mid Tower Case ($59.99 @ Newegg)
Power Supply: OCZ ModXStream Pro 600W 80 PLUS Certified ATX12V / EPS12V Power Supply ($76.47 @ Amazon)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($19.96 @ Amazon)
Total: $916.35
(Prices include shipping, taxes, and discounts when available.)

why dont you try I7 may be the price may high but it will be very usefull for gaming

All you need for gaming is an i5-3570k or FX-8350. Hell, even a FX-6300 will play any game paired with a good GPU.

You don't need a high end CPU as much as a GPU to play games. The i7 is more useful for multi-threaded applications such as video rendering (no not silly montages), 3D modeling & animation, VMware, etc. Its better than the i5 in performance but gaming performance is roughly the same. No video game is really threaded to use more than 1-2 cores. You don't need the i7's hyper-threading for that.

Get an i5 3350P? Good enough for gaming and cheaper than an i7.

For that price range, you'd be better with a FX-8320 or 8350. The only reason you should spend more than the FX is if you can afford the unlocked i5 CPU and a z77 motherboard for over clocking.

Do you plan to OC?

Then I'd go AMD. I wouldn't get an i5 unless you plan to OC. I'd go AMD on the GPU too if you're going to game.

Hold on a second. I'm picking some parts. Will give you a nice theme.