Is this a good computer?

That's not a good pc for gaming, because it has a low end card, you'll need a much better card, if you can build one yourself see this list(all from Canada) : http://ca.pcpartpicker.com/p/E1Ny

It's not good. You can build better yourself.

i5 3350P can be switched with i5 3550.

8GB DDR3 1333 can be switched with 8GB DDR3 1600.

GTX 650 can be switched with at least GTX 650Ti or even GTX 660 if you have the extra cash.

You're both forgetting the OS cost. I have a feeling you're going to have to lower the CPU and go with a 7850. Or drop to 4GB of ram and a less expensive PSU.

In the future you can either OC the CPU [buying a cooler for $20 like the 212+] or upgrade to Steamroller
You could crossfire 7850's on this PSU but a bit risky if CPU is OC at the same time

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($133.06 @ DirectCanada)
Motherboard: Asus M5A97 LE R2.0 ATX AM3+ Motherboard ($77.00 @ Canada Computers)
Memory: Crucial Ballistix sport 8GB (2 x 4GB) DDR3-1600 Memory ($39.99 @ Newegg Canada)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($64.99 @ Canada Computers)
Video Card: Gigabyte Radeon HD 7850 2GB Video Card ($176.42 @ DirectCanada)
Case: BitFenix Merc Alpha (Black) ATX Mid Tower Case ($32.99 @ Canada Computers)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($62.67 @ DirectCanada)
Optical Drive: LG GH24NS72 DVD/CD Writer ($17.06 @ DirectCanada)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($99.99 @ Newegg Canada)
Total: $704.17
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-02-17 01:05 EST-0500)

Heavier GPU but with an i3 you can later upgrade to an i5

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i3-3220 3.3GHz Dual-Core Processor ($116.99 @ Amazon Canada)
Motherboard: ASRock B75M-GL Micro ATX LGA1155 Motherboard ($54.99 @ Canada Computers)
Memory: Crucial Ballistix sport 8GB (2 x 4GB) DDR3-1600 Memory ($39.99 @ Newegg Canada)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($64.99 @ Canada Computers)
Video Card: Gigabyte GeForce GTX 660 2GB Video Card ($205.75 @ DirectCanada)
Case: BitFenix Merc Alpha (Black) ATX Mid Tower Case ($32.99 @ Canada Computers)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($62.67 @ DirectCanada)
Optical Drive: LG GH24NS72 DVD/CD Writer ($17.06 @ DirectCanada)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($99.99 @ Newegg Canada)
Total: $695.42
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-02-17 01:09 EST-0500)