It's not particularly impressive, but pretty good for the money. The only potential issue I see is that you've selected a "K" series CPU. The Intel CPUs with a K suffix are unlocked, meaning they can be overclocked. There is no danger with selecting such a CPU if you do not plan on overclocking it, but the same non-K version of that CPU runs $20 cheaper. If you do want to go with the K CPU, you may want to find out if the motherboard supports overclocking.

Yeah in fact you can't overclock with that motherboard (H77 cannot overclock) so either get a better motherboard (Z77 can overclock) or get a non-K processor.

Edit: I just saw the above post and I'm pretty sure you can't overclock.
Edit 2: I looked it up and it can overclock. Oops.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU:  Intel Core i5-3570K 3.4GHz Quad-Core Processor  ($169.99 @ Microcenter)
Motherboard:  ASRock H77M Micro ATX  LGA1155 Motherboard  ($59.99 @ Newegg)
Memory:  G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1866 Memory  ($49.99 @ Newegg)
Storage:  Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive  ($69.99 @ NCIX US)
Video Card:  EVGA GeForce GTX 650 Ti 1GB Video Card  ($149.99 @ NCIX US)
Case:  NZXT Source 210 Elite (White) ATX Mid Tower Case  ($49.99 @ Amazon)
Power Supply:  Rosewill Capstone 450W 80 PLUS Gold Certified ATX12V / EPS12V Power Supply  ($59.99 @ Amazon)
Optical Drive:  Lite-On iHAS124-04 DVD/CD Writer  ($17.99 @ SuperBiiz)
Operating System:  Microsoft Windows 7 Home Premium SP1 (64-bit)  ($91.99 @ Amazon)
Total: $729.91
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2012-11-21 16:53 EST-0500)

My moms friend asked me to try and make a good computer for gaming for around $700. This is what I came up with. What do you guys think will it be able to do pretty good or do i need to change it?

It can run Starcraft Brood War, so it's good.

If more recent games are preferable, then this seems kinda fine in general too I guess. I am not sure if games like Crysis will run at very good framerate if maxed out, but I have a 1st gen i7 and a weaker video card (I think), and most games I tried other than Crysis ran at about 50+ FPS with everything maxed out. Starcraft II only starts to lag if I play 4 vs 4 on Fastest Map Ever or if a mothership comes out in late games.

The only thing that worried me was the PSU.  You don't want to have your PSU maxed or nearly maxed out.

Good enough to play everything out there with >100fps I guess

Mmm, just returned to this forum and found a post right up my ballpark

This would be a better build:

PCPartPicker part list: http://pcpartpicker.com/p/phaS
Price breakdown by merchant: http://pcpartpicker.com/p/phaS/by_merchant/
Benchmarks: http://pcpartpicker.com/p/phaS/benchmarks/

CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor  ($169.99 @ Microcenter)
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler  ($14.99 @ Newegg)
Motherboard: ASRock Z77 Extreme4 ATX  LGA1155 Motherboard  ($104.99 @ Newegg)
Memory: Samsung 8GB (2 x 4GB) DDR3-1600 Memory  ($34.99 @ Newegg)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  ($69.99 @ Newegg)
Video Card: Asus Radeon HD 7850 2GB Video Card  ($197.06 @ NCIX US)
Case: NZXT Source 210 Elite (White) ATX Mid Tower Case  ($39.99 @ Amazon)
Power Supply: PC Power & Cooling Silencer MK III 500W 80 PLUS Bronze Certified ATX12V Power Supply  ($49.99 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer  ($19.98 @ Outlet PC)
Total: $701.97
(Prices include shipping, taxes, and discounts when available.)

CPU: The 3570K is just the plain standard for gaming. You don't need 3770K's hyperthreading for gaming, and it's understood that AMD's 8core bulldozer is an absolute failure. You can only get this price in store at microcenter, or it's $200. Make sure you have a microcenter near by. Also, if you buy this CPU with any Z77 motherboard at Microcenter, you get an extra $40 off. So please, make the drive to the nearest microcenter (unless it's like 50 miles away, then you'd have to order it online and you can't get the discount).

CPU Cooler: The Hyper 212+ is the best budget CPU cooler. Ringing it at only $15 during these black friday sales, it's a great steal. It can push the 3570K to about 4.5Ghz at 70C under load. That's pretty good for $15.

Motherboard: The Z77 Extreme4 is a decent board for overclocking. I have one, and I have my CPU at 5Ghz stable, using an air cooler. This board is only $64 IF you buy it at microcenter with the 3570K, $40 off price 

RAM: This ram is called the "secret ram". It's not very well known when it first came out, but when people got their hands on it, it easily clocks to 2133mhz from its stock 1600mhz. It has no silly heatsinks and is low profile so it can sit below any CPU cooler.

HDD: This Seagate 2TB hard drive is reliable, quiet, fast, and has ample storage for whatever you want to put on there. It's oddly cheaper than its 1TB counterpart.

GPU: The 7850 destroys the GTX 650Ti in everything. This asus version of the card comes with 2 silent fans. It get 50-60 frames on skyrim. It can also overclock to 1.1ghz, 240mhz more than stock.

Case: Good choice on the Source 210. I highly recommend it. With its great build quality, easy cable management, and good looks, it's definitely a winner.

PSU: Rosewill's PSUs aren't as reliable as PC Power & Cooling's, a subdivision of OCZ. This PSU has 500 watts, modular cable management (connect only the cables you need), and is 80plus bronze. It comes with a free CD/DVD drive I would sell/get rid of since it isn't very good.

CD/DVD Drive: This Asus CD/DVD drive is silent, writes very fast, and is reliable.

This computer is much more powerful, 2x more storage, a LOT more overclockable, and can literally play any game you throw at it. If you get the parts from microcenter, remember to subtract $40. Also, if you sell of the CD/DVD drive that comes with the PSU, you get an extra $15. So in the end, it really costs $646, but I did not add Windows. You could get Windows 8 for like $60 right now iirc. I hope you see the part choices I made, thank you for reading my build, best of luck, and most importantly, have fun.

Mmm, just returned to this forum and found a post right up my ballpark

This would be a better build:

PCPartPicker part list: http://pcpartpicker.com/p/phaS
Price breakdown by merchant: http://pcpartpicker.com/p/phaS/by_merchant/
Benchmarks: http://pcpartpicker.com/p/phaS/benchmarks/

CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor  ($169.99 @ Microcenter)
CPU Cooler: Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler  ($14.99 @ Newegg)
Motherboard: ASRock Z77 Extreme4 ATX  LGA1155 Motherboard  ($104.99 @ Newegg)
Memory: Samsung 8GB (2 x 4GB) DDR3-1600 Memory  ($34.99 @ Newegg)
Storage: Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  ($69.99 @ Newegg)
Video Card: Asus Radeon HD 7850 2GB Video Card  ($197.06 @ NCIX US)
Case: NZXT Source 210 Elite (White) ATX Mid Tower Case  ($39.99 @ Amazon)
Power Supply: PC Power & Cooling Silencer MK III 500W 80 PLUS Bronze Certified ATX12V Power Supply  ($49.99 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer  ($19.98 @ Outlet PC)
Total: $701.97
(Prices include shipping, taxes, and discounts when available.)

CPU: The 3570K is just the plain standard for gaming. You don't need 3770K's hyperthreading for gaming, and it's understood that AMD's 8core bulldozer is an absolute failure. You can only get this price in store at microcenter, or it's $200. Make sure you have a microcenter near by. Also, if you buy this CPU with any Z77 motherboard at Microcenter, you get an extra $40 off. So please, make the drive to the nearest microcenter (unless it's like 50 miles away, then you'd have to order it online and you can't get the discount).

CPU Cooler: The Hyper 212+ is the best budget CPU cooler. Ringing it at only $15 during these black friday sales, it's a great steal. It can push the 3570K to about 4.5Ghz at 70C under load. That's pretty good for $15.

Motherboard: The Z77 Extreme4 is a decent board for overclocking. I have one, and I have my CPU at 5Ghz stable, using an air cooler. This board is only $64 IF you buy it at microcenter with the 3570K, $40 off price 

RAM: This ram is called the "secret ram". It's not very well known when it first came out, but when people got their hands on it, it easily clocks to 2133mhz from its stock 1600mhz. It has no silly heatsinks and is low profile so it can sit below any CPU cooler.

HDD: This Seagate 2TB hard drive is reliable, quiet, fast, and has ample storage for whatever you want to put on there. It's oddly cheaper than its 1TB counterpart.

GPU: The 7850 destroys the GTX 650Ti in everything. This asus version of the card comes with 2 silent fans. It get 50-60 frames on skyrim. It can also overclock to 1.1ghz, 240mhz more than stock.

Case: Good choice on the Source 210. I highly recommend it. With its great build quality, easy cable management, and good looks, it's definitely a winner.

PSU: Rosewill's PSUs aren't as reliable as PC Power & Cooling's, a subdivision of OCZ. This PSU has 500 watts, modular cable management (connect only the cables you need), and is 80plus bronze. It comes with a free CD/DVD drive I would sell/get rid of since it isn't very good.

CD/DVD Drive: This Asus CD/DVD drive is silent, writes very fast, and is reliable.

This computer is much more powerful, 2x more storage, a LOT more overclockable, and can literally play any game you throw at it. If you get the parts from microcenter, remember to subtract $40. Also, if you sell of the CD/DVD drive that comes with the PSU, you get an extra $15. So in the end, it really costs $646, but I did not add Windows. You could get Windows 8 for like $60 right now iirc. I hope you see the part choices I made, thank you for reading my build, best of luck, and most importantly, have fun.

Wish a saw this a couple days ago...
I already ordered the parts though. I'll keep this in mind if I decide to  build another one though.